title: Emergency department

text: Because time is such an essential factor in emergency treatment, EDs typically have their own diagnostic equipment to avoid waiting for equipment installed elsewhere in the hospital. Nearly all have radiographic examination rooms staffed by dedicated Radiographer, and many now have full radiology facilities including CT scanners and ultrasonography equipment. Laboratory services may be handled on a priority basis by the hospital lab, or the ED may have its own "STAT Lab" for basic labs (blood counts, blood typing, toxicology screens, etc.) that must be returned very rapidly.


title: Emergency department

text: Metrics applicable to the ED can be grouped into three main categories, volume, cycle time, and patient satisfaction. Volume metrics including arrivals per hour, percentage of ED beds occupied, and age of patients are understood at a basic level at all hospitals as an indication for staffing requirements. Cycle time metrics are the mainstays of the evaluation and tracking of process efficiency and are less widespread since an active effort is needed to collect and analyze this data. Patient satisfaction metrics, already commonly collected by nursing groups, physician groups, and hospitals, are useful in demonstrating the impact of changes in patient perception of care over time. Since patient satisfaction metrics are derivative and subjective, they are less useful in primary process improvement. Health information exchanges can reduce nonurgent ED visits by supplying current data about admissions, discharges, and transfers to health plans and accountable care organizations, allowing them to shift ED use to primary care settings.


title: Emergency department

text: In all primary care trusts there are out of hours medical consultations provided by general practitioners or nurse practitioners.


title: Emergency department

text: In the United States, high costs are incurred by non-emergency use of the emergency room. The National Hospital Ambulatory Medical Care Survey looked at the ten most common symptoms for which giving rise to emergency room visits (cough, sore throat, back pain, fever, headache, abdominal pain, chest pain, other pain, shortness of breath, vomiting) and made suggestions as to which would be the most cost-effective choice among virtual care, retail clinic, urgent care, or emergency room. Notably, certain complaints may also be addressed by a telephone call to a person's primary care provider.


title: Emergency department

text: In the United States, and many other countries, hospitals are beginning to create areas in their emergency rooms for people with minor injuries. These are commonly referred as "Fast Track" or "Minor Care" units. These units are for people with non-life-threatening injuries. The use of these units within a department have been shown to significantly improve the flow of patients through a department and to reduce waiting times. Urgent care clinics are another alternative, where patients can go to receive immediate care for non-life-threatening conditions. To reduce the strain on limited ED resources, American Medical Response created a checklist that allows EMTs to identify intoxicated individuals who can be safely sent to detoxification facilities instead.


title: Emergency department

text: Emergency department overcrowding is when function of a department is hindered by an inability to treat all patients in an adequate manner. This is a common occurrence in emergency departments worldwide. Overcrowding causes inadequate patient care which leads to poorer patient outcomes. To address this problem, escalation policies are used by emergency departments when responding to an increase in demand (e.g., a sudden inflow of patients) or a reduction in capacity (e.g., a lack of beds to admit patients). The policies aim to maintain the ability to deliver patient care, without compromising safety, by modifying "normal" processes.


title: Emergency department

text: Emergency department (ED) waiting times have a serious impact on patient mortality, morbidity with readmission in less than 30 days, length of stay, and patient satisfaction. The probability of death increases each 3 minutes for 1% in case of major injuries in the abdomen part. (Journal of Trauma and Acute Care Surgery) Equipment in emergency departments follows the prompt treatment principle with the least possible patient transfers from admittance to X-ray diagnostics. A review of the literature bears out the logical premise that since the outcome of treatment for all diseases and injuries is time-sensitive, the sooner treatment is rendered, the better the outcome. Various studies reported significant associations between waiting times and higher mortality and morbidity among those who survived. It is clear from the literature that untimely hospital deaths and morbidity can be reduced by reductions in ED waiting times.


title: Emergency department

text: While a significant proportion of people attending emergency departments are discharged home after treatment, many require admission for ongoing observation or treatment, or to ensure adequate social care before discharge is possible. If people requiring admission are not able to be moved to inpatient beds swiftly, "exit block" or "access block" occurs. This often leads to crowding and impairs flow to the point that it can lead to delays in appropriate treatment for newly presenting cases ("arrival access block"). This phenomenon is more common in densely populated areas, and affects pediatric departments less than adults ones.


title: Emergency department

text: Exit block can lead to delays in care both in the people awaiting inpatient beds ("boarding") and those who newly present to an exit blocked department. Various solutions have been proposed, such as changes in staffing or increasing inpatient capacity.


title: Emergency department

text: Frequent flyers are persons who will present themselves at a hospital multiple times, usually those with complex medical requirements or with psychological issues complicating medical management. These persons contribute to overcrowding and typically require more hospital resources although they do not account for a significant number of visits. To help prevent inappropriate emergency department use and return visits, some hospitals offer care coordination and support services such as at-home and in-shelter transitional primary care for frequent flyers and short-term housing for homeless patients recovering after discharge.


title: Emergency department

text: One study found that the implementation of telemedicine services in Saudi Arabia showed to be effective in reducing emergency department overload by providing medical advices to less- and non-urgent patients and deal with their minor medical issues.


title: Emergency department

text: Emergency departments in the military benefit from the added support of enlisted personnel who are capable of performing a wide variety of tasks they have been trained for through specialized military schooling. For example, in United States Military Hospitals, Air Force Aerospace Medical Technicians and Navy Hospital Corpsmen perform tasks that fall under the scope of practice of both doctors (i.e. sutures, staples and incision and drainages) and nurses (i.e. medication administration, foley catheter insertion, and obtaining intravenous access) and also perform splinting of injured extremities, nasogastric tube insertion, intubation, wound cauterizing, eye irrigation, and much more. Often, some civilian education and/or certification will be required such as an EMT certification, in case of the need to provide care outside the base where the member is stationed. The presence of highly trained enlisted personnel in an Emergency Departments drastically reduces the workload on nurses and doctors.


title: Emergency department

text: According to a survey at an urban inner-city tertiary care centre in Vancouver, 57% of health care workers were physically assaulted in 1996. 73% were afraid of patients as a result of violence, 49% hid their identities from patients, 74% had reduced job satisfaction. Over one-quarter of the respondents took days off because of violence. Of respondents no longer working in the emergency department, 67% reported that they had left the job at least partly owing to violence. Twenty-four-hour security and a workshop on violence prevention strategies were felt to be the most useful potential interventions. Physical exercise, sleep and the company of family and friends were the most frequent coping strategies cited by those surveyed.


title: Emergency department

text: Medication errors are issues that lead to incorrect medication distribution or potential for patient harm. As of 2014, around 3% of all hospital-related adverse effects were due to medication errors in the emergency department (ED); between 4% and 14% of medications given to patients in the ED were incorrect and children were particularly at risk.


title: Emergency department

text: Errors can arise if the doctor prescribes the wrong medication, if the prescription intended by the doctor is not the one actually communicated to the pharmacy due to an illegibly-written prescription or misheard verbal order, if the pharmacy dispenses the wrong medication, or if the medication is then given to the wrong person.


title: Emergency department

text: The ED is a riskier environment than other areas of the hospital due to medical practitioners not knowing the patient as well as they know longer term hospital patients, due to time pressure caused by overcrowding, and due to the emergency-driven nature of the medicine that is practiced there.


title: Mr. Pickles

text: Mr. Pickles is an American adult animated sitcom created by Will Carsola and Dave Stewart for Adult Swim. The series revolves around the Goodman family, especially their 6-year-old son named Tommy and the family's border collie dog, the demonic Mr. Pickles. The series aired from September 21, 2014 to November 18, 2019.


title: Mr. Pickles

text: The first episode of season 4 was a surprise series finale, replacing the show with a new spin-off series titled "Momma Named Me Sheriff".


title: Mr. Pickles

text: In the small, old-fashioned community of Old Town, the Goodman family and their innocent and dimwitted 6-year-old son Tommy have a satanic border collie dog named Mr. Pickles. The two spend their days romping around Old Town, while unknown to Tommy, the family or anyone Mr. Pickles tolerates – except for Tommy's grandfather – Mr. Pickles secretly slips away to kill and mutilate his countless victims. Mr. Pickles will often reassemble and resurrect his victims which then reside in his underground lair and do his bidding. Through his evil, murderous rampage against those that threaten his boy, get in his way or annoy him, Mr. Pickles brings some order to Old Town, which is otherwise riddled with crime in the face of the dimwitted sheriff.


title: Mr. Pickles

text: The series, which is animated using Adobe Flash, was created by Will Carsola and Dave Stewart – known for "Funny or Die Presents" – and executive-produced by Will Carsola, Dave Stewart, and Michael J. Rizzo. The series was one of several shows pitched to Adult Swim, according to the creators, who also operate under the name "Day by Day". Stewart recalled promoting it as a "one-line sentence", while Carsola remembered that it derived from a "write-off" session, where the two present ideas to each other in the form of scribbles for their amusement. Carsola explained that ideas in this process are released from the pressure "of them being good", occasionally finding "one that sticks". They later explained at the 2014 San Diego Comic-Con International that the idea was based on "Lassie", but has become "more of its own thing since then."


title: Mr. Pickles

text: Stewart's own female Australian Cattle Dog served as inspiration for the animators on the character of Mr. Pickles. Stewart even pointed out similarities between her and the main character, and jokingly called her "Ms. Pickles". Animation director Mike L. Mayfield recorded Stewart's dog playing around on video, with animators using the resulting footage as a basis for the character's movements. Its setting is roughly based on Richmond, Virginia, where the creators started out in entertainment before moving to Los Angeles. The creators are given creative freedom by the network, with Stewart explaining the notes received by them as "minimal", much to their surprise. The creators observed some inconsistencies as to what is considered unacceptable, but try not to question it and compromise instead.


title: Mr. Pickles

text: Elaborating on its 11-minute running time, Carsola described it as a 22-minute show "squished" into a quarter-hour. Among the voices for the characters include Brooke Shields, Frank Collison, Jay Johnston and Carsola and Stewart themselves. Shields' role in the series came after looking at the creator's work for "Funny or Die" and obtaining the script for "Mr. Pickles". According to Carsola, the two were dubious over her interest in the series, but after being cast she provided lines in a recording booth in New York City while the creators supervised over Skype.


title: Mr. Pickles

text: The series was picked up for ten quarter-hour episodes for its first season, premiering on the network on September 21, 2014 following the ninth-season premiere of "Squidbillies". In July 2013, the pilot episode was released online as part of a presentation of in-development shows for the network, partnered with KFC; viewers could vote for their favorite pilot, with the winner being broadcast on August 26, 2013. The series lost to "Übermansion", a Stoopid Buddy Stoodios production, although the presentation as a whole won an Internet Advertising Campaign Award in 2014 for "Best TV Integrated Ad Campaign". The pilot was later published on the network's website on January 23, 2014, and on YouTube on March 10 of the same year, becoming viral with over 700,000 views after roughly a month later. A second season was mentioned at the 2014 Comic-Con.


title: Mr. Pickles

text: Aaron Simpson of "Cold Hard Flash" called the series an amalgamation of "Lassie" and "Superjail!", while observing some social commentary "to ensure this is more than just a multi-episodic sketch." Mike Hale of "The New York Times" labeled it "the less tasteful but more mainstream" counterpart to "Tim & Eric's Bedtime Stories", another addition to the network. He wrote that the show was "more grisly than funny," but predicted it to have a cult following and that Shields' voice would add "surreal-pop-culture cachet".


title: Mr. Pickles

text: In Australia, the series premiered on August 3, 2015 on The Comedy Channel, and then moved to the free to air Adult Swim block on 9Go!


title: Mr. Pickles

text: In April 2017, a trailer was released promoting the season 3 premiere to air in fall 2017; however, this was later pushed back, for unknown reasons, to the following year. The first episode of season three premiered on February 26, 2018. The show was renewed for a fourth season, before the third one even premiered.


title: Erotic spanking

text: Erotic spanking is the act of spanking another person for the sexual arousal or gratification of either or both parties. The intensity of the act can vary in both its duration and severity, and may include the use of one or more spanking implements (such as the wooden spoon or cane). Activities range from a spontaneous smack on bare buttocks during sexual activity to sexual roleplaying, such as ageplay or domestic discipline. Erotic spanking is often found within and associated with BDSM, however the activity is not exclusive to it. The term "spankee" is commonly used within erotic spanking to refer to the individual receiving a spanking.


title: Erotic spanking

text: One of the earliest depictions of erotic spanking is found in the Etruscan Tomb of the Whipping from the fifth century BC.


title: Erotic spanking

text: Early sex manuals such as the Indian Kama Sutra (circa 400 BC), Indian Koka Shastra (ca. 1150 AD) and Arabic The Perfumed Garden (ca. 1400 AD) have among their recommendations the use of spanking to enhance sexual arousal.


title: Erotic spanking

text: Interest in sexual gratification received from giving, receiving and witnessing spanking began to increase during the 19th century (particularly within France and the United Kingdom). Interest was not only confined to spanking literature, but the development of photography during 19th century resulted in the beginning of the creation of spanking photography. In the context of literature, this growing demand caused the publication of numerous limited edition spanking novels (although, while the term novel is/was used many of these works from this time and subsequently can be instead classified as novellas).


title: Erotic spanking

text: This interest for spanking (both in regards to literature and photography) followed into the next century, with the early 20th century being considered the "Golden Age" of spanking literature. This period of spanking literature is marked by three notable characteristics. First, greater audiences were reached with the availability of less expensive editions and greater print runs. Second, many of the spanking novels contained numerous illustrations (many of which have fallen under public domain and are easily available online). Third, this period saw a gradual increase in the output and publication of spanking literature, growing particularly within the 1920s and peaking within the 1930s. Much of the output of spanking literature during this period was by French publishers, writers and illustrators. Similarly, within the context of spanking photography, France was also the home to the creation of much content, with the most notable studios being the Biederer Studio and the Ostra Studio. This "Golden Age" of spanking literature (and French spanking photography) came to an end as a result of the Second World War, more specifically due to the German occupation of France between 1940 and 1944 and later the enforcement of censorship laws. A somewhat notable exception to the decline of spanking literature during this period was John Willie's bondage "Bizarre" magazine (published between 1946 and 1959).


title: Erotic spanking

text: Of the many French works from the "Golden Age" few at the time were translated into other languages within which spanking literature was popular, namely English and German, but beginning during the mid-1960s a number of these French works were translated into English and published, along with these works being republished in French and older British works also being republished. The occurrence of this was facilitated by the availability of mass-produced paperbacks and changes in censorship laws.


title: Erotic spanking

text: During the latter half of the 20th century changes in both censorship laws and improvements within technology enabled greater accessibility for those interested in obtaining content related to erotic spanking.


title: Erotic spanking

text: As an extension of the earlier developments within spanking literature and photography, during this period various fetish magazines devoted to stories and imagery of erotic spanking became legally available.


title: Erotic spanking

text: This period also saw an important development in both the production and consumer accessibility of erotic spanking films. Whilst recordings of erotic spanking had been produced as early as the 1920s, until the 1980s technology limited the quality of their recording and the ability for consumers to easily watch them. In addition to changes in censorship laws, the introduction of the videocassette recorder enabled creators to produce and distribute erotic spanking films that were far easier for consumers to both obtain and watch.


title: Erotic spanking

text: The proliferation of the internet has enabled individuals, of various level of pre-existing interest and/or knowledge, more ease then ever to explore and consume content relating to erotic spanking.


title: Erotic spanking

text: Partially developing from earlier erotic spanking magazine and video producers, numerous pornographic websites (primary American or British based) within the 21st century are devoted to producing spanking films of various lengths and about various scenarios.


title: Erotic spanking

text: The internet has also resulted in the creation of various blogs which discuss the topic of erotic spanking and non-profit websites which publish erotic spanking stories.


title: Erotic spanking

text: Whilst a spanking may be simply given with the palm of the hand, the use of spanking implements is common within erotic spanking. Spanking implements which are commonly used within erotic spanking are a reflection of the traditional spanking implements that were/are used in corporal punishment more broadly. Common and traditional spanking implements include those which have been specifically manufactured for such purpose (i.e. the cane, paddle, strap, tawse and martinet) and those which have been adapted/improvised from available items (such as the slipper, wooden spoon, hairbrush, carpet beater, switch and birch). Other less common and atypical spanking implements include the feather duster (common, however, in China), fly swatter, stinging nettles, and rolled-up magazines or newspapers.


title: Erotic spanking

text: Some spanking implements can be characterised as being either 'stingy' or 'thuddy'. Stingy implements (such as a cane) produce a sharp and quick burning sensation which is mostly felt on the skin. Thuddy implements (such as a paddle), in contrast, whilst not producing a stinging sensation penetrate deeper into tissue of the buttocks. As a general rule, the heavier a spanking implement is the greater thud it will produce. A person receiving an erotic spanking may have a preference for either a stingy or thuddy sensation.


title: Erotic spanking

text: For safety, during a spanking, particularly with spanking implements, care should be taken to avoid striking the tailbone and hipbones.


title: Erotic spanking

text: Often erotic spanking will be combined with sexual roleplay which may see one or more party dress-up in certain clothing, for example a female "spankee" wearing a schoolgirl uniform in a Teacher – Student scenario.


title: Erotic spanking

text: A spank skirt or spanking skirt is a skirt that has an additional opening in back designed to expose the buttocks. While the name "spank skirt" suggests the intention that the wearer be spanked "bare bottom" without removing or repositioning the skirt, this item may be worn for reasons other than spanking (for instance, exposure). Considered fetish wear, these kind of skirts are typically tight-fitting and made of fetishistic materials (such as leather, PVC or latex). Regardless of the gender of the wearer, spank skirts are usually considered female attire. The male gender role equivalent might be motorcycle chaps (a.k.a. "assless chaps").


title: Erotic spanking

text: A spanking bench or spanking horse is a piece of erotic furniture used to position a "spankee" on, with or without restraints. They come in many sizes and styles, the most popular design of which is similar to a sawhorse (used in woodworking) with a padded top and rings for restraints. A spanking bench is on permanent display at the Leather Archives and Museum. The 19th-century British dominatrix Mrs. Theresa Berkley became famous for her invention of the Berkley Horse, a similar form of BDSM apparatus.


title: Erotic spanking

text: Occasionally, self-spanking also occurs. This can happen in a BDSM relationship on the orders of the dominant partner and is thus part of a role play, or the person simply wants to feel pain in a certain way. However, that's when the "self-tickling effect" comes into play: you practically can't tickle yourself. This is because the brain anticipates our movements and touches. If there is an expectation that we are about to touch ourselves on a certain part of the body, the brain adjusts and dampens the sensation. This effect exists just as much with painful actions: When we hit ourselves, it doesn't hurt as much because here too the brain automatically reduces the sensation.


title: Erotic spanking

text: A number of explanations have been put forward to account why an individual may enjoy erotic spanking, although there is likely no universal explanation. Journalist Jillian Keenan has argued that spanking fetishism is a form of sexual orientation, which should not be considered a mental illness. Whilst there has been an increasing ability to talk openly about erotic spanking within mainstream society, individuals may still find it difficult to express that they have an interest in erotic spanking.


title: Erotic spanking

text: Since there are also connections to pain sensations through blows to the buttocks, molecular mechanisms can be found as factors for sexual behaviour related to this. Parents pass on information to their offspring not only via the DNA sequence, but also epigenetically with the sperm and eggs, via biological factors that regulate the DNA. This has not yet been proven in humans, but it has been in mice. Swiss researchers showed that trauma in childhood does indeed affect the composition of the blood throughout life and that these changes are also inherited by the offspring. Other researchers found that the neurotransmitter dopamine has an epigenetic function beyond its role as a signal transducer. In rats, dopamine was found to control drug-seeking behaviour. Long-term cocaine use alters neural circuits in the brain's reward pathway. This requires genes to be switched on and off to create the necessary proteins - an epigenetic process.


title: Erotic spanking

text: Dopamine also plays an important role in the perception of pain. According to this, children who received corporal punishment more often form fewer dopamine receptors in a specific brain area. The dopamine system is closely associated with pleasure perception. Normally, then, the dopamine system should be capable of multiple activation. However, children who are beaten frequently develop a dopamine receptor deficiency, so that their pleasure system becomes susceptible to stronger stimuli. A scientific survey of 152 people who claimed to practice sadomasochism - of which spanking is a subset - found that 22% had been abused or beaten with objects as children. 78%, however, reported having developed this interest on their own (intrinsically) often in childhood and adolescence.


title: Erotic spanking

text: Finally, for a preference of spanking, there is the assumption that the brain then releases endorphins. If one gets spanked significantly and frequently - which then leads to equally frequent and intense bursts of endorphins, an addiction to, for example, butt slaps and the accompanying endorphin release can result. Over time, they associate the blows with not only pleasurable but also erotic feelings.


title: Erotic spanking

text: Cortisol is a hormone that helps the body prepare to fight, flee or freeze in the face of danger. Children who are beaten have no way to flee or fight - they must submit to the pain and violence. Physical punishment triggers the release of cortisol. Repeated increases in cortisol can make it easier to endure danger and pain. This can also lead to downplaying violence-associated childhood experiences as an adult. Researchers now found a group of girls who had experienced physical discipline did not have the expected increase in cortisol. Instead, they showed a huge increase in the hormone oxytocin.


title: Prose Edda

text: The Prose Edda, also known as the Younger Edda, Snorri's Edda () or, historically, simply as Edda, is an Old Norse textbook written in Iceland during the early 13th century. The work is often assumed to have been to some extent written, or at least compiled, by the Icelandic scholar, lawspeaker, and historian Snorri Sturluson 1220. It is considered the fullest and most detailed source for modern knowledge of Norse mythology, the body of myths of the North Germanic peoples, and draws from a wide variety of sources, including versions of poems that survive into today in a collection known as the "Poetic Edda".


title: Prose Edda

text: The "Prose Edda" consists of four sections: The Prologue, a euhemerized account of the Norse gods; "Gylfaginning", which provides a question and answer format that details aspects of Norse mythology (consisting of approximately 20,000 words), "Skáldskaparmál", which continues this format before providing lists of kennings and "heiti" (approximately 50,000 words); and "Háttatal", which discusses the composition of traditional skaldic poetry (approximately 20,000 words).


title: Prose Edda

text: Dating from 1300 to 1600, seven manuscripts of the "Prose Edda" differ from one another in notable ways, which provides researchers with independent textual value for analysis. The "Prose Edda" appears to have functioned similarly to a contemporary textbook, with the goal of assisting Icelandic poets and readers in understanding the subtleties of alliterative verse, and to grasp the meaning behind the many kennings used in skaldic poetry.


title: Prose Edda

text: Originally known to scholars simply as "Edda", the "Prose Edda" gained its contemporary name in order to differentiate it from the "Poetic Edda". Early scholars of the "Prose Edda" suspected that there once existed a collection of entire poems, a theory confirmed with the rediscovery of manuscripts of the "Poetic Edda".


title: Prose Edda

text: The etymology of "Edda" remains uncertain; there are many hypotheses about its meaning and developing, yet little agreement. Some argue that the word derives from the name of Oddi, a town in the south of Iceland where Snorri was raised. Edda could therefore mean "book of Oddi." However, this assumption is generally rejected. Anthony Faulkes in his English translation of the Prose Edda comments that this is "unlikely, both in terms of linguistics and history" since Snorri was no longer living at Oddi when he composed his work.


title: Prose Edda

text: Another connection was made with the word "óðr", which means 'poetry or inspiration' in Old Norse. According to Faulkes, though such a connection is plausible semantically, it is unlikely that "Edda" could have been coined in the 13th century on the basis of "óðr", because such a development "would have had to have taken place gradually", and "Edda" in the sense of 'poetics' is not likely to have existed in the preliterary period.


title: Prose Edda

text: Edda also means 'great-grandparent', a word that appears in "Skáldskaparmál", which occurs as the name of a figure in the eddic poem "Rigsthula" and in other medieval texts.


title: Prose Edda

text: A final hypothesis is derived from the Latin "edo", meaning "I write". It relies on the fact that the word ""kredda"" (meaning "belief") is certified and comes from the Latin ""credo"", meaning 'I believe'. "Edda" in this case could be translated as "Poetic Art". This is the meaning that the word was then given in the medieval period.


title: Prose Edda

text: The now uncommonly used name "Sæmundar Edda" was given by the Bishop Brynjólfur Sveinsson to the collection of poems contained in the Codex Regius, many of which are quoted by Snorri. Brynjólfur, along with many others of his time incorrectly believed that they were collected by Sæmundr fróði (therefore before the drafting of the Edda of Snorri), and so the Poetic Edda is also known as the Elder Edda.


title: Prose Edda

text: Seven manuscripts of the "Prose Edda" have survived into the present day: Six copies from the medieval period and another dating to the 1600s. No one manuscript is complete, and each has variations. In addition to three fragments, the four main manuscripts are Codex Regius, Codex Wormianus, Codex Trajectinus, and the Codex Upsaliensis:


title: Prose Edda

text: The other three manuscripts are AM 748; AM 757 a 4to; and AM 738 II 4to, AM le ß fol. Although some scholars have doubted whether a sound stemma of the manuscripts can be created, due to the possibility of scribes drawing on multiple exemplars or from memory, recent work has found that the main sources of each manuscript can be fairly readily ascertained. The "Prose Edda"' remained fairly unknown outside of Iceland until the publication of the "Edda Islandorum" in 1665.


title: Prose Edda

text: The text is often assumed to have been written or at least compiled to some extent by Snorri Sturluson. This identification is largely based on the following paragraph from a portion of Codex Upsaliensis, an early 14th-century manuscript containing the "Edda":


title: Prose Edda

text: Scholars have noted that this attribution, along with that of other primary manuscripts, is not clear whether or not Snorri is more than the compiler of the work and the author of "Háttatal" or if he is the author of the entire "Edda". Faulkes summarizes the matter of scholarly discourse around the authorship of the "Prose Edda" as follows:


title: Prose Edda

text: Whatever the case, the mention of Snorri in the manuscripts has been influential in a common acceptance of Snorri as the author or at least one of the authors of the "Edda".


title: Prose Edda

text: The Prologue is the first section of four books of the "Prose Edda", consisting of a euhemerized Christian account of the origins of Norse mythology: the Nordic gods are described as human Trojan warriors who left Troy after the fall of that city (an origin which parallels Virgil's "Aeneid"). According to the "Prose Edda", these warriors settled in northern Europe, where they were accepted as divine kings because of their superior culture and technology. Remembrance ceremonies later conducted at their burial sites degenerated into heathen cults, turning them into gods.


title: Prose Edda

text: "Gylfaginning" (Old Icelandic 'the tricking of Gylfi') follows the Prologue in the "Prose Edda". "Gylfaginning" deals with the creation and destruction of the world of the Nordic gods, and many other aspects of Norse mythology. The section is written in prose interspersed with quotes from eddic poetry.


title: Prose Edda

text: "Skáldskaparmál" (Old Icelandic 'the language of poetry') is the third section of "Edda", and consists of a dialogue between Ægir, a jötunn who is one of various personifications of the sea, and Bragi, a skaldic god, in which both Norse mythology and discourse on the nature of poetry are intertwined. The origin of a number of kennings are given and Bragi then delivers a systematic list of kennings for various people, places, and things. Bragi then goes on to discuss poetic language in some detail, in particular "heiti", the concept of poetical words which are non-periphrastic, for example "steed" for "horse", and again systematises these. This section contains numerous quotes from skaldic poetry.


title: Prose Edda

text: "Háttatal" (Old Icelandic "list of verse-forms") is the last section of "Prose Edda". The section is composed by the Icelandic poet, politician, and historian Snorri Sturluson. Primarily using his own compositions, it exemplifies the types of verse forms used in Old Norse poetry. Snorri took a prescriptive as well as descriptive approach; he has systematized the material, often noting that the older poets did not always follow his rules.


title: Spinning Out

text: Spinning Out is an American drama streaming television series, created by Samantha Stratton, that premiered on Netflix on January 1, 2020. In February 2020, the series was canceled after one season.


title: Spinning Out

text: The series stars Kaya Scodelario as Kat Baker, a young ice skater who suffers a serious injury and is given the opportunity to restart her career as a pairs skater all while hiding her family's history of mental illness. The series follows the Baker family along with Kat's partner Justin Davis and his family.


title: Spinning Out

text: "Spinning Out" follows Kat Baker, an up-and-coming, high-level single skater who is about to turn in her skates after a disastrous fall took her off the competition track. When Kat seizes an opportunity to continue her career as a pair skater with a talented bad-boy partner, she risks exposing a fiercely kept secret that could unravel her entire life. On and off the ice, Kat and her new partner will face daunting odds, injury to body and soul, financial sacrifice, and even potential mental breakdown on their way to realizing their Olympic dream."


title: Spinning Out

text: On October 11, 2018, it was announced that Netflix had given the production a series order consisting of ten episodes. The series was created by Samantha Stratton who was also expected to serve as co-showrunner with Lara Olsen. Stratton and Olsen were also set to executive produce the series alongside Joby Harold and Tory Tunnell with Matt Schwartz serving as a co-executive producer. Production companies were slated to consist of Safehouse Pictures. On February 3, 2020, it was reported that the series was canceled after one season.


title: Spinning Out

text: Alongside the series order announcement, it was confirmed that Emma Roberts would star in the series. On October 31, 2018, it was reported that Roberts had dropped out of the series, citing a scheduling conflict. In December 2018, it was announced that Kaya Scodelario had been cast to replace Roberts in the role of Kat Baker. It was also reported that Willow Shields, Evan Roderick, Johnny Weir, Sarah Wright Olsen, Will Kemp, Kaitlyn Leeb, Amanda Zhou, and Mitchell Edwards had been cast in series regular roles. On January 16, 2019, it was reported that January Jones had joined the cast in a leading role. On February 21, 2019, it was announced that Svetlana Efremova and Charlie Hewson had been cast in a series regular role and recurring capacity respectively.


title: Spinning Out

text: A number of Canadian figure skaters served as skating doubles for the series' stars, including Michelle Long (singles skating) and Elizabeth Putnam (singles and pairs skating) for Kaya Scodelario as Kat Baker, Kim Deguise Léveillée (jumps) for Scodelario and Willow Shields as Serena Baker, and Dylan Moscovitch for Evan Roderick as Justin Davis. Canadian pair team Evelyn Walsh and Trennt Michaud served as doubles for Kat and Justin's pair elements. Other doubles include Lilika Zheng for Amanda Zhou as Jenn Yu, Emma Cullen for January Jones as Carol Baker, and Madeline Schizas for Kaitlyn Leeb as Leah Starnes.


title: Spinning Out

text: On review aggregation website Rotten Tomatoes, the series has an approval rating of 63% with an average rating of 6.5/10, based on 16 reviews. The website's critical consensus states, "Though at times more melodramatic than meaningful, "Spinning Out" campy, guilty-pleasure exterior hides a surprisingly thoughtful exploration of living with a mental illness." On Metacritic, it has a weighted average score of 47 out of 100, based 4 critics, indicating "mixed or average reviews".


title: Spinning Out

text: Robyn Bahr of "The Hollywood Reporter" called it "Uneven but mostly engrossing, it combines the unflinching class struggles of "I, Tonya", the star-crossed romance of "The Cutting Edge" and the disability-as-tragedy goopiness of "Ice Castles"." Caroline Framke of "Variety" wrote "The series has all the right ingredients for an addictive watch: a solid premise, some compelling actors, and some classic teen show tensions and rhythms in the earnest vein of 'Degrassi' braiding it all together. But as the season plods towards its uneven finale, 'Spinning Out' instead does exactly what its title promises instead of sticking the landing."


title: Special (Lizzo album)

text: Special is the fourth studio album by American singer and rapper Lizzo, released by Nice Life and Atlantic Records on July 15, 2022. It was preceded by the lead single "About Damn Time", released on April 14, 2022, which reached number one on the "Billboard" Hot 100, and the top ten in twelve other countries.


title: Special (Lizzo album)

text: "Special," has been described by critics as a pop, funk, disco, hip hop and R&B album. It received positive reviews from music critics. The album peaked at number two on the US "Billboard" 200 chart, becoming, at the time, the highest-charting album by a female artist in 2022, as well as the largest week by units earned, among all albums released by women in 2022. It reached the top ten on the UK, Australian, Canadian, Hungary, and New Zealand album charts.


title: Special (Lizzo album)

text: Lizzo released her third studio album and major-label debut studio album, "Cuz I Love You", on April 19, 2019. The album was met with critical acclaim and peaked at number four on the "Billboard" 200 chart. The album was nominated for Album of the Year at the 62nd Annual Grammy Awards, contributing to Lizzo receiving the most nominations at the ceremony. The album also won the award for Best Urban Contemporary Album.


title: Special (Lizzo album)

text: In October 2020, Lizzo announced that her fourth studio album was nearing completion, saying she had "a few more songs to write". In January 2021, American singer SZA confirmed to have heard new material from Lizzo. In August 2021, Lizzo announced "Rumors", her first song after two years, which was released on August 13. The standalone single features American rapper, singer, and songwriter Cardi B.


title: Special (Lizzo album)

text: During her keynote speech at the South by Southwest festival in March 2022, Lizzo announced that her album was finished, saying "It’s done so it’s coming very very soon…and it’s good. I worked real hard on it, so it better be good."


title: Special (Lizzo album)

text: Recording for "Special" began in 2018, but the tracks that made up the album only started to be recorded in September 2021 and was finished by March 2022.


title: Special (Lizzo album)

text: In an interview with Zane Lowe for Apple Music 1 in April 2022, Lizzo explained that the album was originally titled "In Case Nobody Told You" until Max Martin helped her "restructure" the hook of the song "Special", which she then changed the title of the album to.


title: Special (Lizzo album)

text: In another interview with Zane Lowe on Apple Music 1 in July 2022, Lizzo talked about the origins of the track "Coldplay", with Coldplay lead singer Chris Martin appearing in the interview as well. The track features a monologue by Lizzo where she talks about a recent vacation in which she "was with somebody, and I was just looking at the stars. And I was with him, and I was singing ["Yellow"]."


title: Special (Lizzo album)

text: On March 21, 2022, Lizzo previewed the single "About Damn Time" on "The Late Late Show with James Corden", with a release date of April 14. Shortly after the release of the song and its accompanying music video, Lizzo formally announced "Special", with a release date of July 15.


title: Special (Lizzo album)

text: On July 6, Lizzo revealed the tracklist of "Special" on her Instagram account by showing the back cover of its vinyl packaging.


title: Special (Lizzo album)

text: "About Damn Time" was released on April 14, 2022, as the lead single of the album. The song was a commercial success peaking at the top of The Billboard Hot 100 in the US as well as reaching top 3 in 7 other countries.


title: Special (Lizzo album)

text: On July 18, 2022 "2 Be Loved (Am I Ready)" was released to Italian radio as the album's second single. In the United States the song impacted hot adult contemporary radio on August 1, 2022 and contemporary hit radio, as well as rhythmic contemporary radio on August 2, 2022.


title: Special (Lizzo album)

text: On April 25, 2022, Lizzo announced a full arena tour in support of the album, starting on September 23, 2022, in Sunrise, Florida and ending on November 19, 2022, in Inglewood, California. Latto will open for the tour.


title: Special (Lizzo album)

text: "Special" received generally positive reviews from music critics upon its initial release. At Metacritic, which assigns a normalized rating out of 100 to reviews from mainstream critics, the album has an average score of 78, based on 16 reviews, indicating "generally favorable reviews".


title: Special (Lizzo album)

text: Writing for "Evening Standard" David Smyth states that "This time she'll sweep an older generation into her gang too. Many of the biggest tunes channel Seventies disco and Eighties synthpop" and added "It's clear she isn’t an outsider any more. This is her world, and we're lucky to live in it." In an article for "The Independent", reviewer Helen Brown pointed that "Special" is overflowing with love and gratitude to friends, family, lovers and fans and added that [Lizzo's] rap flow has a terrific tensile strength and said that when singing, she delivers as both a belter and a breathy balladeer. Special is good as hell." "NME" contributor Nick Levine gave the album four out of five stars, observing that "Lizzo's overwhelmingly positive message, "Special" is sometimes a bit cheesy," before concluding that "Lizzo knows exactly who she is as an artist and what she wants to achieve: she's the bad bitch with an incredible talent for making people feel good". In a more mixed reception of the album, Sam Franzini of "The Line of Best Fit" believed that for "most songs on Special, there is a rawer, more real iteration somewhere else in Lizzo’s catalog," and that having the "glossiest pop sheen steamrolled over them, erasing any wrinkles or mishaps" removed "the exact thing that made [Lizzo's songs] endearing to begin with." "PopMatters" published two contrasting reviews of the album, with John Amen scoring the album 7/10 and commenting that ""Special" is as much a celebration of the Twitter, Instagram, and Facebook cosmos as it is an in-person, post-Covid bacchanal." while Nick Malone scored the album 4/10 and wrote that ""Special" is such a disappointment because you can hear the better album Lizzo is capable of making."


title: Special (Lizzo album)

text: The song "Grrrls" earned controversy for its use of the word "spaz" in its lyrics "I'mma spaz / I'm about to knock somebody out". Disability advocates viewed the use of the term "spaz" as an offensive ableist slur and called for Lizzo to remove the song. Some internet users claimed that "spaz" is used differently in African-American Vernacular English and is synonymous with "freaking out," but disability organizations in the UK and the US have criticized its use. Shortly afterwards, Lizzo issued an apology and released an updated version of the song, stating, "I never want to promote derogatory language." The updated song lyrics replace "I'mma spaz" with "Hold me back".


title: Special (Lizzo album)

text: In the United States, "Special" debuted at number two on the US "Billboard" 200 chart, with 69,000 equivalent album units sold in its first week, becoming Lizzo's highest-charting album to date. It was the highest charting album by a female artist in 2022, as well as the largest week by units earned, among all albums released by women in 2022 until it was surpassed by Beyoncé's "Renaissance".


title: Melina Kanakaredes

text: Melina Eleni Kanakaredes Constantinides (; born April 23, 1967) is an American actress. She is widely known for her roles in U.S. primetime television dramas as Dr. Sydney Hansen in "Providence" (1999–2002), as Detective Stella Bonasera in "" (2004–2010), and on the American daytime television drama series "Guiding Light" as Eleni Andros Cooper (1991–1995).


title: Melina Kanakaredes

text: Kanakaredes was born in Akron, Ohio, the daughter of Connie (née Temo), a candy company owner, and Harry Kanakaredes, an insurance salesman. She is a second-generation Greek-American and speaks Greek fluently. Her two maternal uncles own and run a candy store in Akron called "Temo's Candy Company", a chocolate store established in its current location by Kanakaredes's grandfather, Christ Temo.


title: Melina Kanakaredes

text: At age eight, Kanakaredes made her stage debut in a production of "Tom Sawyer" at Weathervane Playhouse in Akron, Ohio. She graduated from the Firestone High School in Akron. She attended The Ohio State University for a short time, and then transferred to Point Park College in Pittsburgh, Pennsylvania, where she performed roles in the professional theatre scene there, including the role of Mary Magdalene in "Jesus Christ Superstar" at Pittsburgh Musical Theater. She graduated from Point Park in 1989 with a Bachelor of Arts degree in theater arts.


title: Melina Kanakaredes

text: Kanakaredes's first television role was on the daytime drama "Guiding Light", originating the role of Eleni Andros Cooper from 1991 to 1995. She was nominated twice for a Daytime Emmy Award for her portrayal of Eleni.


title: Melina Kanakaredes

text: Her most high-profile roles on television were as the series protagonist Dr. Sydney Hansen on "Providence", which ran for five seasons between 1999 and 2002, and as Det. Stella Bonasera on the CBS drama series "". Kanakaredes left "CSI: NY" in 2010, after six seasons on the program.


title: Melina Kanakaredes

text: Other television credits include "NYPD Blue" (in a recurring role as reporter Benita Alden during that show's second season), "Due South", "Oz", "The Practice", MTV's "The Ben Stiller Show", a Hallmark Hall of Fame adaptation of the Anne Tyler novel "Saint Maybe", and Dr Lane Hunter on the Amy Holden Jones TV series "The Resident".


title: Melina Kanakaredes

text: Kanakaredes's film appearances include "The Long Kiss Goodnight" as Trin and "15 Minutes" as Nicolette Karas, the girlfriend of Robert De Niro's character. She was considered for the lead role in "My Big Fat Greek Wedding" but had to turn it down due to her pregnancy.


title: Melina Kanakaredes

text: She played the role of the Greek Goddess Athena in "" and starred in the 2013 drama "Snitch" alongside Dwayne (The Rock) Johnson.


title: Melina Kanakaredes

text: Kanakaredes married Peter Constantinides on September 6, 1992. Together, they have two daughters: Zoe (b. 2000) and Karina Eleni (b. 2003). She and her husband, a former restaurant consultant, owned the "Tria Greek Kuzina" in Powell, Ohio, but it has since closed.


title: Gary Crosby (actor)

text: Gary Evan Crosby (June 27, 1933 – August 24, 1995) was an American actor and singer. His parents were Bing Crosby, of whom he wrote a highly critical memoir, and the singer and actress Dixie Lee.


title: Gary Crosby (actor)

text: Gary Crosby was born in Los Angeles, California, and graduated from Stanford University. He entered the entertainment business and performed in a harmony singing group, The Crosby Boys, with his three brothers, Philip, Lindsay, and Dennis, during the 1940s, 1950s, and 1960s. As a teenager, he duetted with his father on two songs, "Sam's Song" and "Play a Simple Melody", which became the first double-sided gold record in history. He also recorded duets with Louis Armstrong and at least one 45-single with Sammy Davis Jr. He also performed on several variety programs, including ABC's "The Pat Boone Chevy Showroom" and NBC's "The Ford Show, Starring Tennessee Ernie Ford.


title: Gary Crosby (actor)

text: In the mid-1950s, he had his own radio program, the "Gary Crosby Show" on CBS. The musical variety program debuted June 6, 1954, as a summer replacement for Bing Crosby's show.


title: Gary Crosby (actor)

text: As an actor, Crosby appeared in many television programs. On March 20, 1955, he appeared on "The Jack Benny Program" Season 5, Episode 13. Later, he was briefly under contract to 20th Century-Fox in the late 1950s. He appeared in a number of supporting roles for the studio, normally comedies in which Crosby played a soldier: "Mardi Gras" (1958) with Pat Boone; "Holiday for Lovers" (1959), as Carol Lynley's love interest; "A Private's Affair" (1959), with Sal Mineo; "The Right Approach" (1961) with Frankie Vaughan.


title: Gary Crosby (actor)

text: He is perhaps best-remembered for his recurring roles as Eddie the scheming bellhop on "The Bill Dana Show" and Officer Edward "Ed" Wells on NBC's "Adam-12" from 1968 to 1975, as well as appearances on several other shows produced by Jack Webb's Mark VII Limited (including an episode of "Dragnet 1969" and five episodes of "Emergency!"). In addition to the aforementioned, he also appeared in three episodes of "The Rockford Files". Crosby appeared in, "In The Heat Of The Night", as Mal Tabert, in When The Music Stopped, as manager of Robert Goulet, who shoots and kills a stalker in 1992.


title: Gary Crosby (actor)

text: In 1965, he made a guest appearance on "Perry Mason" as singer Jazbo Williams in "The Case of the Frustrated Folk Singer". He appeared in "Girl Happy" (1965), starring Elvis Presley, with whom he had been stationed in the Army in Germany.


title: Gary Crosby (actor)

text: In 1964, Crosby appeared in the last filmed episode of "The Twilight Zone". Entitled "Come Wander with Me", the episode co-starred Bonnie Beecher (in her very first role) and was directed by Richard Donner.


title: Gary Crosby (actor)

text: Gary also made an appearance in his father's 1964 sitcom, "The Bing Crosby Show" in the second episode as a lookalike. In the 1970s, he appeared occasionally on game shows such as "Match Game" and "Tattletales" as a guest panelist. He married and divorced three times; he had one stepchild as a result.


title: Gary Crosby (actor)

text: In 1983, six years after his father's death, Crosby published an autobiography, "Going My Own Way", which revealed the effects of his alcoholism and his difficult childhood as a result of his mother's alcoholism and his father's emotional and physical abuse.


title: Gary Crosby (actor)

text: Shortly before Gary's book was actually published, Lindsay said, "I'm glad [Gary] did it. I hope it clears up a lot of the old lies and rumors." Unlike Gary, Lindsay stated that he preferred to remember "all the good things I did with my dad and forget the times that were rough".


title: Gary Crosby (actor)

text: Bing's younger brother, singer and jazz bandleader Bob Crosby, recalled at the time of Gary's revelations that Bing was a "disciplinarian", as their mother and father had been. He added, "We were brought up that way." In an interview for the same article, Gary clarified that Bing "was like a lot of fathers of that time. He was not out to be vicious, to beat children for his kicks."


title: Gary Crosby (actor)

text: The author of the most recent biography on Bing Crosby, Gary Giddins, claims that Gary Crosby's memoir is not reliable on many instances and cannot be trusted on the abuse stories.


title: Gary Crosby (actor)

text: Gary Crosby died of lung cancer in Burbank, California in 1995, and is interred at Forest Lawn-Hollywood Hills Cemetery.


title: Binoculars

text: Binoculars or field glasses are two refracting telescopes mounted side-by-side and aligned to point in the same direction, allowing the viewer to use both eyes (binocular vision) when viewing distant objects. Most binoculars are sized to be held using both hands, although sizes vary widely from opera glasses to large pedestal-mounted military models.


title: Binoculars

text: Unlike a (monocular) telescope, binoculars give users a three-dimensional image: each eyepiece presents a slightly different image to each of the viewer's eyes and the parallax allows the visual cortex to generate an impression of depth.


title: Binoculars

text: Almost from the invention of the telescope in the 17th century the advantages of mounting two of them side by side for binocular vision seems to have been explored. Most early binoculars used Galilean optics; that is, they used a convex objective and a concave eyepiece lens. The Galilean design has the advantage of presenting an erect image but has a narrow field of view and is not capable of very high magnification. This type of construction is still used in very cheap models and in opera glasses or theater glasses. The Galilean design is also used in low magnification binocular surgical and jewelers' loupes because they can be very short and produce an upright image without extra or unusual erecting optics, reducing expense and overall weight. They also have large exit pupils, making centering less critical, and the narrow field of view works well in those applications. These are typically mounted on an eyeglass frame or custom-fit onto eyeglasses.


title: Binoculars

text: An improved image and higher magnification are achieved in binoculars employing Keplerian optics, where the image formed by the objective lens is viewed through a positive eyepiece lens (ocular).


title: Binoculars

text: Since the Keplerian configuration produces an inverted image, different methods are used to turn the image the right way up.


title: Binoculars

text: In aprismatic binoculars with Keplerian optics (which were sometimes called "twin telescopes"), each tube has one or two additional lenses (relay lens) between the objective and the eyepiece. These lenses are used to erect the image. The binoculars with erecting lenses had a serious disadvantage: they are too long. Such binoculars were popular in the 1800s (for example, G.& S. Merz models). The Keplerian "twin telescopes" binoculars were optically and mechanically hard to manufacture, but it took until the 1890s to supersede them with better prism-based technology.


title: Binoculars

text: Optical prisms added to the design enabled the display of the image the right way up without needing as many lenses, and decreasing the overall length of the instrument, typically using Porro prism or roof prism systems. The Italian optical inventor of optical instruments Ignazio Porro worked during the 1860s with Hofmann in Paris to produce monoculars using the same prism configuration used in modern Porro prism binoculars. At the 1873 Vienna Trade Fair German optical designer and scientist Ernst Abbe displayed a prism telescope with two cemented Porro prisms. The optical solutions of Porro and Abbe were theoretically sound, but the employed prism systems failed in practice primarily due to insufficient glass quality.


title: Binoculars

text: "Porro prism binoculars" are named after Ignazio Porro, who patented this image erecting system in 1854. The later refinement by Ernst Abbe and his cooperation with glass scientist Otto Schott and instrument maker Carl Zeiss resulted in 1894 in the commercial introduction of improved 'modern' Porro prism binoculars by the Carl Zeiss company. Binoculars of this type use a pair of Porro prisms in a Z-shaped configuration to erect the image. This results in wide binoculars, with objective lenses that are well separated and offset from the eyepieces, giving a better sensation of depth. Porro prism designs have the added benefit of folding the optical path so that the physical length of the binoculars is less than the focal length of the objective. Porro prism binoculars were made in such a way to erect an image in a relatively small space, thus binoculars using prisms started in this way.


title: Binoculars

text: Porro prisms require typically within 10 arcminutes ( of 1 degree) tolerances for alignment of their optical elements (collimation) at the factory. Sometimes Porro prisms binoculars need their prisms set to be re-aligned to bring them into collimation. Good-quality Porro prism design binoculars often feature about deep grooves or notches ground across the width of the hypotenuse face center of the prisms, to eliminate image quality reducing abaxial non-image-forming reflections. Porro prism binoculars can offer good optical performance with relatively little manufacturing effort and as human eyes are ergonomically limited by their interpupillary distance the offset and separation of big (60 mm wide) diameter objective lenses and the eyepieces becomes a practical advantage in a stereoscopic optical product.


title: Binoculars

text: In the early 2020s, the commercial market share of Porro prism-type binoculars had become the second most numerous compared to other prism-type optical designs.


title: Binoculars

text: There are alternative Porro prism-based systems available that find application in binoculars on a small scale, like the Perger prism that offers a significantly reduced axial offset compared to traditional Porro prism designs .


title: Binoculars

text: "Roof prism binoculars" may have appeared as early as the 1870s in a design by Achille Victor Emile Daubresse. In 1897 Moritz Hensoldt began marketing pentaprism based roof prism binoculars.


title: Binoculars

text: Most roof prism binoculars use either the Schmidt–Pechan prism (invented in 1899) or the Abbe–Koenig prism (named after Ernst Karl Abbe and Albert König and patented by Carl Zeiss in 1905) designs to erect the image and fold the optical path. They have objective lenses that are approximately in a line with the eyepieces.


title: Binoculars

text: Binoculars with roof prisms have been in use to a large extent since the second half of the 20th century. Roof prism designs result in objective lenses that are almost or totally in line with the eyepieces, creating an instrument that is narrower and more compact than Porro prisms and lighter. There is also a difference in image brightness. Porro prism and Abbe–Koenig roof-prism binoculars will inherently produce a brighter image than Schmidt–Pechan roof prism binoculars of the same magnification, objective size, and optical quality, because the Schmidt-Pechan roof-prism design employs mirror-coated surfaces that reduce light transmission.


title: Binoculars

text: In roof prism designs, optically relevant prism angles must be correct within 2 arcseconds ( of 1 degree) to avoid seeing an obstructive double image. Maintaining such tight production tolerances for the alignment of their optical elements by laser or interference (collimation) at an affordable price point is challenging. To avoid the need for later re-collimation, the prisms are generally aligned at the factory and then permanently fixed to a metal plate. These complicating production requirements make high-quality roof prism binoculars more costly to produce than Porro prism binoculars of equivalent optical quality and until phase correction coatings were invented in 1988 Porro prism binoculars optically offered superior resolution and contrast to non-phase corrected roof prism binoculars.


title: Binoculars

text: In the early 2020s, the commercial offering of Schmidt-Pechan designs exceeds the Abbe-Koenig design offerings and had become the dominant optical design compared to other prism-type designs.


title: Binoculars

text: Alternative roof prism-based designs like the Uppendahl prism system composed of three prisms cemented together were and are commercially offered on a small scale.


title: Binoculars

text: Although different prism systems have optical design-induced advantages and disadvantages when compared, due to technological progress in fields like optical coatings, optical glass manufacturing, etcetera, differences in the early 2020s in high-quality binoculars practically became irrelevant. At high-quality price points, similar optical performance can be achieved with every commonly applied optical system. This was 20–30 years earlier not possible, as occurring optical disadvantages and problems could at that time not be technically mitigated to practical irrelevancy. Relevant differences in optical performance in the sub-high-quality price categories can still be observed with roof prism-type binoculars today because well-executed technical problem mitigation measures and narrow manufacturing tolerances remain difficult and cost-intensive.


title: Binoculars

text: Binoculars are usually designed for specific applications. These different designs require certain optical parameters which may be listed on the prism cover plate of the binoculars. Those parameters are:


title: Binoculars

text: Given as the first number in a binocular description (e.g., 7×35, 10×50), magnification is the ratio of the focal length of the objective divided by the focal length of the eyepiece. This gives the magnifying power of binoculars (sometimes expressed as "diameters"). A magnification factor of 7, for example, produces an image 7 times larger than the original seen from that distance. The desirable amount of magnification depends upon the intended application, and in most binoculars is a permanent, non-adjustable feature of the device (zoom binoculars are the exception). Hand-held binoculars typically have magnifications ranging from 7× to 10×, so they will be less susceptible to the effects of shaking hands. A larger magnification leads to a smaller field of view and may require a tripod for image stability. Some specialized binoculars for astronomy or military use have magnifications ranging from 15× to 25×.


title: Binoculars

text: Given as the second number in a binocular description (e.g., 7×35, 10×50), the diameter of the objective lens determines the resolution (sharpness) and how much light can be gathered to form an image. When two different binoculars have equal magnification, equal quality, and produce a sufficiently matched exit pupil (see below), the larger objective diameter produces a "brighter" and sharper image. An 8×40, then, will produce a "brighter" and sharper image than an 8×25, even though both enlarge the image an identical eight times. The larger front lenses in the 8×40 also produce wider beams of light (exit pupil) that leave the eyepieces. This makes it more comfortable to view with an 8×40 than an 8×25. A pair of 10×50 binoculars is better than a pair of 8×40 binoculars for magnification, sharpness and luminous flux. Objective diameter is usually expressed in millimeters. It is customary to categorize binoculars by the "magnification" × "the objective diameter"; e.g., "7×50". Smaller binoculars may have a diameter of as low as 22 mm; 35 mm and 50 mm are common diameters for field binoculars; astronomical binoculars have diameters ranging from 70 mm to 150 mm.


title: Binoculars

text: The field of view of a pair of binoculars depends on its optical design and in general is inversely proportional to the magnifying power. It is usually notated in a linear value, such as how many feet (meters) in width will be seen at 1,000 yards (or 1,000 m), or in an angular value of how many degrees can be viewed.


title: Binoculars

text: Binoculars concentrate the light gathered by the objective into a beam, of which its diameter, the exit pupil, is the objective diameter divided by the magnifying power. For maximum effective light-gathering and brightest image, and to maximize the sharpness, the exit pupil should at least equal the diameter of the pupil of the human eye: about 7 mm at night and about 3 mm in the daytime, decreasing with age. If the cone of light streaming out of the binoculars is "larger" than the pupil it is going into, any light larger than the pupil is wasted. In daytime use, the human pupil is typically dilated about 3 mm, which is about the exit pupil of a 7×21 binocular. Much larger 7×50 binoculars will produce a (7.14 mm) cone of light bigger than the pupil it is entering, and this light will, in the daytime, be wasted. An exit pupil that is too "small" also will present an observer with a dimmer view, since only a small portion of the light-gathering surface of the retina is used. For applications where equipment must be carried (birdwatching, hunting), users opt for much smaller (lighter) binoculars with an exit pupil that matches their expected iris diameter so they will have maximum resolution but are not carrying the weight of wasted aperture.


title: Binoculars

text: A larger exit pupil makes it easier to put the eye where it can receive the light; anywhere in the large exit pupil cone of light will do. This ease of placement helps avoid, especially in large field of view binoculars, vignetting, which brings to the viewer an image with its borders darkened because the light from them is partially blocked, and it means that the image can be quickly found, which is important when looking at birds or game animals that move rapidly, or for a seafarer on the deck of a pitching vessel or observing from a moving vehicle. Narrow exit pupil binoculars also may be fatiguing because the instrument must be held exactly in place in front of the eyes to provide a useful image. Finally, many people use their binoculars at dawn, at dusk, in overcast conditions, or at night, when their pupils are larger. Thus, the daytime exit pupil is not a universally desirable standard. For comfort, ease of use, and flexibility in applications, larger binoculars with larger exit pupils are satisfactory choices even if their capability is not fully used by day.


title: Binoculars

text: Before innovations like anti-reflective coatings were commonly used in binoculars, their performance was often mathematically expressed. Nowadays, the practically achievable instrumentally measurable brightness of binoculars rely on a complex mix of factors like the quality of optical glass used and various applied optical coatings and not just the magnification and the size of objective lenses.


title: Binoculars

text: The twilight factor for binoculars can be calculated by first multiplying the magnification by the objective lens diameter and then finding the square root of the result. For instance, the twilight factor of 7×50 binoculars is therefore the square root of 7 × 50: the square root of 350 = 18.71. The higher the twilight factor, mathematically, the better the resolution of the binoculars when observing under dim light conditions. Mathematically, 7×50 binoculars have exactly the same twilight factor as 70×5 ones, but 70×5 binoculars are useless during twilight and also in well-lit conditions as they would offer only a 0.14 mm exit pupil. The twilight factor without knowing the accompanying more decisive exit pupil does not permit a practical determination of the low light capability of binoculars. Ideally, the exit pupil should be at least as large as the pupil diameter of the user's dark-adapted eyes in circumstances with no extraneous light.


title: Binoculars

text: A primarily historic, more meaningful mathematical approach to indicate the level of clarity and brightness in binoculars was relative brightness. It is calculated by squaring the diameter of the exit pupil. In the above 7×50 binoculars example, this means that their relative brightness index is 51 (7.14 × 7.14 = 51). The higher the relative brightness index number, mathematically, the better the binoculars are suited for low light use.


title: Binoculars

text: Eye relief is the distance from the rear eyepiece lens to the exit pupil or eye point. It is the distance the observer must position his or her eye behind the eyepiece in order to see an unvignetted image. The longer the focal length of the eyepiece, the greater the potential eye relief. Binoculars may have eye relief ranging from a few millimeters to 25 mm or more. Eye relief can be particularly important for eyeglasses wearers. The eye of an eyeglasses wearer is typically farther from the eye piece which necessitates a longer eye relief in order to avoid vignetting and, in the extreme cases, to conserve the entire field of view. Binoculars with short eye relief can also be hard to use in instances where it is difficult to hold them steady.


title: Binoculars

text: Eyeglasses wearers who intend to wear their glasses when using binoculars should look for binoculars with an eye relief that is long enough so that their eyes are not behind the point of focus (also called the eyepoint). Else, their glasses will occupy the space where their eyes should be. Generally, an eye relief over 16 mm should be adequate for any eyeglass wearer. However, if glasses frames are thicker and so significantly protrude from the face, an eye relief over 17 mm should be considered. Eyeglasses wearers should also look for binoculars with twist-up eye cups that ideally have multiple settings, so they can be partially or fully retracted to adjust eye relief to individual ergonomic preferences.


title: Binoculars

text: Close focus distance is the closest point that the binocular can focus on. This distance varies from about , depending upon the design of the binoculars. If the close focus distance is short with respect to the magnification, the binocular can be used also to see particulars not visible to the naked eye.


title: Binoculars

text: Binocular eyepieces usually consist of three or more lens elements in two or more groups. The lens furthest from the viewer's eye is called the "field lens" or "objective lens" and that closest to the eye the "eye lens" or "ocular lens". The most common configuration is that invented in 1849 by Carl Kellner. In this arrangement, the eye lens is a plano-concave/ double convex achromatic doublet (the flat part of the former facing the eye) and the field lens is a double-convex singlet. A reversed Kellner eyepiece was developed in 1975 and in it the field lens is a double concave/ double convex achromatic doublet and the eye lens is a double convex singlet. The reverse Kellner provides 50% more eye relief and works better with small focal ratios as well as having a slightly wider field.


title: Binoculars

text: Wide field binoculars typically utilize some kind of Erfle configuration, patented in 1921. These have five or six elements in three groups. The groups may be two achromatic doublets with a double convex singlet between them or may all be achromatic doublets. These eyepieces tend not to perform as well as Kellner eyepieces at high power because they suffer from astigmatism and ghost images. However they have large eye lenses, excellent eye relief, and are comfortable to use at lower powers.


title: Binoculars

text: High-end binoculars often incorporate a field flattener lens in the eyepiece behind their prism configuration, designed to improve image sharpness and reduce image distortion at the outer regions of the field of view.


title: Binoculars

text: Binoculars have a focusing arrangement which changes the distance between eyepiece and objective lenses or internally mounted lens elements. Normally there are two different arrangements used to provide focus, "independent focus" and "central focusing":


title: Binoculars

text: With increasing magnification, the depth of field – the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image – decreases. The depth of field reduces quadratic with the magnification, so compared to 7× binoculars, 10× binoculars offer about half (7² ÷ 10² = 0.49) the depth of field. However, not related to the binoculars optical system, the user perceived practical depth of field or depth of acceptable view performance is also dependent on the accommodation ability (accommodation ability varies from person to person and decreases significantly with age) and light conditions dependent effective pupil size or diameter of the user's eyes.


title: Binoculars

text: There are "focus-free" or "fixed-focus" binoculars that have no focusing mechanism other than the eyepiece adjustments that are meant to be set for the user's eyes and left fixed. These are considered to be compromise designs, suited for convenience, but not well suited for work that falls outside their designed hyperfocal distance range (for hand held binoculars generally from about to infinity without performing eyepiece adjustments for a given viewer).


title: Binoculars

text: Binoculars can be generally used without eyeglasses by myopic (near-sighted) or hyperopic (far-sighted) users simply by adjusting the focus a little farther. Most manufacturers leave a little extra available focal-range beyond the infinity-stop/setting to account for this when focusing for infinity. People with severe astigmatism, however, will still need to use their glasses while using binoculars.


title: Binoculars

text: Some binoculars have adjustable magnification, "zoom binoculars", such as 7-21×50 intended to give the user the flexibility of having a single pair of binoculars with a wide range of magnifications, usually by moving a "zoom" lever. This is accomplished by a complex series of adjusting lenses similar to a zoom camera lens. These designs are noted to be a compromise and even a gimmick since they add bulk, complexity and fragility to the binocular. The complex optical path also leads to a narrow field of view and a large drop in brightness at high zoom. Models also have to match the magnification for both eyes throughout the zoom range and hold collimation to avoid eye strain and fatigue. These almost always perform much better at the low power setting than they do at the higher settings. This is natural, since the front objective cannot enlarge to let in more light as the power is increased, so the view gets dimmer. At 7×, the 50mm front objective provides a 7.14 mm exit pupil, but at 21×, the same front objective provides only a 2.38 mm exit pupil. Also, the optical quality of a zoom binocular at any given power is inferior to that of a fixed power binocular of that power.


title: Binoculars

text: Most modern binoculars are also adjustable via a hinged construction that enables the distance between the two telescope halves to be adjusted to accommodate viewers with different eye separation or "interpupillary distance (IPD)" (the distance measured in millimeters between the centers of the pupils of the eyes). Most are optimized for the interpupillary distance (typically about 63 mm) for adults. Interpupillary distance varies with respect to age, gender and race. The binoculars industry has to take IPD variance (most adults have IPDs in the 50–75 mm range) and its extrema into account, because stereoscopic optical products need to be able to cope with many possible users, including those with the smallest and largest IPDs.


title: Binoculars

text: Children and adults with narrow IPDs can experience problems with the IPD adjustment range of binocular barrels to match the width between the centers of the pupils in each eye impairing the use of some binoculars. Adults with average or wide IPDs generally experience no eye separation adjustment range problems, but straight barreled roof prism binoculars featuring over 60 mm diameter objectives can dimensionally be problematic to correctly adjust for adults with a relatively narrow IPDs. Anatomic conditions like hypertelorism and hypotelorism can affect IPD and due to extreme IPDs result in practical impairment of using stereoscopic optical products like binoculars.


title: Binoculars

text: The two telescopes in binoculars are aligned in parallel (collimated), to produce a single circular, apparently three-dimensional, image. Misalignment will cause the binoculars to produce a double image. Even slight misalignment will cause vague discomfort and visual fatigue as the brain tries to combine the skewed images.


title: Binoculars

text: Alignment is performed by small movements to the prisms, by adjusting an internal support cell or by turning external set screws, or by adjusting the position of the objective via eccentric rings built into the objective cell.


title: Binoculars

text: "Unconditional aligning" (3-axis collimation, meaning both optical axes are aligned parallel with the axis of the hinge used to select various interpupillary distance settings) binoculars requires specialized equipment. Unconditional alignment is usually done by a professional, although the externally mounted adjustment features can usually be accessed by the end user.


title: Binoculars

text: "Conditional alignment" ignores the third axis (the hinge) in the alignment process. Such a conditional alignment comes down to a 2-axis pseudo-collimation and will only be serviceable within a small range of interpupillary distance settings, as conditional aligned binoculars are not collimated for the full interpupillary distance setting range.


title: Binoculars

text: Some binoculars use image-stabilization technology to reduce shake at higher magnifications. This is done by having a gyroscope move part of the instrument, or by powered mechanisms driven by gyroscopic or inertial detectors, or via a mount designed to oppose and damp the effect of shaking movements. Stabilization may be enabled or disabled by the user as required. These techniques allow binoculars up to 20× to be hand-held, and much improve the image stability of lower-power instruments. There are some disadvantages: the image may not be quite as good as the best unstabilized binoculars when tripod-mounted, stabilized binoculars also tend to be more expensive and heavier than similarly specified non-stabilised binoculars.


title: Binoculars

text: Binoculars housings can be made of various structural materials. Old binoculars barrels and hinge bridges were often made of brass. Later steel and relatively light metals like aluminum and magnesium alloys were used, as well as polymers like (fibre-reinforced) polycarbonate and acrylonitrile butadiene styrene. The housing can be rubber armored externally as outer covering to provide a non-slip gripping surface, absorption of undesired sounds and additional cushioning/protection against dents, scrapes, bumps and minor impacts.


title: Binoculars

text: Because a typical binocular has 6 to 10 optical elements with special characteristics and up to 20 atmosphere-to-glass surfaces, binocular manufacturers use different types of optical coatings for technical reasons and to improve the image they produce.


title: Binoculars

text: Lens and prism optical coatings on binoculars can increase light transmission, minimize detrimental reflections and interference effects, optimize beneficial reflections, repel water and grease and even protect the lens from scratches. Modern optical coatings are composed of a combination of very thin layers of materials such as oxides, metals, or rare earth materials. The performance of an optical coating is dependent on the number of layers, manipulating their exact thickness and composition, and the refractive index difference between them. These coatings have become a key technology in the field of optics and manufacturers often have their own designations for their optical coatings. The various lens and prism optical coatings used in high-quality 21st century binoculars, when added together, can total about 200 (often superimposed) coating layers.


title: Binoculars

text: Anti-reflective interference coatings reduce light lost at every optical surface through reflection at each surface. Reducing reflection via anti-reflective coatings also reduces the amount of "lost" light present inside the binocular which would otherwise make the image appear hazy (low contrast). A pair of binoculars with good optical coatings may yield a brighter image than uncoated binoculars with a larger objective lens, on account of superior light transmission through the assembly. The first transparent interference-based coating "Transparentbelag (T)" used by Zeiss was invented in 1935 by Olexander Smakula. A classic lens-coating material is magnesium fluoride, which reduces reflected light from about 4% to 1.5%. At 16 atmosphere to optical glass surfaces passes, a 4% reflection loss theoretically means a 52% light transmission ( = 0.520) and a 1.5% reflection loss a much better 78.5% light transmission ( = 0.785). Reflection can be further reduced over a wider range of wavelengths and angles by using several superimposed layers with different refractive indices. The anti-reflective multi-coating "Transparentbelag* (T*)" used by Zeiss in the late 1970s consisted of six superimposed layers. In general, the outer coating layers have slightly lower index of refraction values and the layer thickness is adapted to the range of wavelengths in the visible spectrum to promote optimal destructive interference via reflection in the beams reflected from the interfaces, and constructive interference in the corresponding transmitted beams. There is no simple formula for the optimal layer thickness for a given choice of materials. These parameters are therefore determined with the help of simulation programs. Determined by the optical properties of the lenses used and intended primary use of the binoculars, different coatings are preferred, to optimize light transmission dictated by the human eye luminous efficiency function variance. Maximal light transmission around wavelengths of 555 nm (green) is important for obtaining optimal photopic vision using the eye cone cells for observation in well-lit conditions. Maximal light transmission around wavelengths of 498 nm (cyan) is important for obtaining optimal scotopic vision using the eye rod cells for observation in low light conditions. As a result, effective modern anti-reflective lens coatings consist of complex multi-layers and reflect only 0.25% or less to yield an image with maximum brightness and natural colors. These allow high-quality 21st century binoculars to practically achieve at the eye lens or ocular lens measured over 90% light transmission values in low light conditions. Depending on the coating, the character of the image seen in the binoculars under normal daylight can either look "warmer" or "colder" and appear either with higher or lower contrast. Subject to the application, the coating is also optimized for maximum color fidelity through the visible spectrum, for example in the case of lenses specially designed for bird watching.


title: Binoculars

text: A common application technique is physical vapor deposition of one or more superimposed anti-reflective coating layer(s) which includes evaporative deposition, making it a complex production process.


title: Binoculars

text: In binoculars with roof prisms the light path is split into two paths that reflect on either side of the roof prism ridge. One half of the light reflects from roof surface 1 to roof surface 2. The other half of the light reflects from roof surface 2 to roof surface 1. If the roof faces are uncoated, the mechanism of reflection is Total Internal Reflection (TIR). In TIR, light polarized in the plane of incidence (p-polarized) and light polarized orthogonal to the plane of incidence (s-polarized) experience different phase shifts. As a consequence, linearly polarized light emerges from a roof prism elliptically polarized. Furthermore, the state of elliptical polarization of the two paths through the prism is different. When the two paths recombine on the retina (or a detector) there is interference between light from the two paths causing a distortion of the Point Spread Function and a deterioration of the image. Resolution and contrast significantly suffer. These unwanted interference effects can be suppressed by vapor depositing a special dielectric coating known as a "phase-correction coating" or "P-coating" on the roof surfaces of the roof prism. To approximately correct a roof prism for polychromatic light several phase-correction coating layers are superimposed, since every layer is wavelength and angle of incidence specific.


title: Binoculars

text: Other manufacturers followed soon, and since then phase-correction coatings are used across the board in medium and high-quality roof prism binoculars. This coating suppresses the difference in phase shift between s- and p- polarization so both paths have the same polarization and no interference degrades the image. In this way, since the 1990s, roof prism binoculars have also achieved resolution values that were previously only achievable with Porro prisms. The presence of a phase-correction coating can be checked on unopened binoculars using two polarization filters. Dielectric phase-correction prism coatings are applied in a vacuum chamber with maybe thirty or more different superimposed vapor coating layers deposits, making it a complex production process.


title: Binoculars

text: Binoculars using either a Schmidt–Pechan roof prism, Abbe–Koenig roof prism or an Uppendahl roof prism benefit from phase coatings that compensate for a loss of resolution and contrast caused by the interference effects that occur in untreated roof prisms. Porro prism and Perger prism binoculars do not split beams and therefore they do not require any phase coatings.


title: Binoculars

text: In binoculars with Schmidt–Pechan or Uppendahl roof prisms, mirror coatings are added to some surfaces of the roof prism because the light is incident at one of the prism's glass-air boundaries at an angle less than the critical angle so total internal reflection does not occur. Without a mirror coating most of that light would be lost. Roof prism aluminum mirror coating (reflectivity of 87% to 93%) or silver mirror coating (reflectivity of 95% to 98%) is used.


title: Binoculars

text: In older designs silver mirror coatings were used but these coatings oxidized and lost reflectivity over time in unsealed binoculars. Aluminum mirror coatings were used in later unsealed designs because they did not tarnish even though they have a lower reflectivity than silver. Using vacuum-vaporization technology, modern designs use either aluminum, enhanced aluminum (consisting of aluminum overcoated with a multilayer dielectric film) or silver. Silver is used in modern high-quality designs which are sealed and filled with nitrogen or argon to provide an inert atmosphere so that the silver mirror coating does not tarnish.


title: Binoculars

text: Porro prism and Perger prism binoculars and roof prism binoculars using the Abbe–Koenig roof prism configuration do not use mirror coatings because these prisms reflect with 100% reflectivity using total internal reflection in the prism rather than requiring a (metallic) mirror coating.


title: Binoculars

text: Dielectric coatings are used in Schmidt–Pechan and Uppendahl roof prisms to cause the prism surfaces to act as a dielectric mirror. This coating was introduced in 2004 in Zeiss Victory FL binoculars featuring Schmidt–Pechan prisms. Other manufacturers followed soon, and since then dielectric coatings are used across the board in medium and high-quality Schmidt–Pechan and Uppendahl roof prism binoculars. The non-metallic dielectric reflective coating is formed from several multilayers of alternating high and low refractive index materials deposited on a prism's reflective surfaces. The manufacturing techniques for dielectric mirrors are based on thin-film deposition methods. A common application technique is physical vapor deposition which includes evaporative deposition with maybe seventy or more different superimposed vapor coating layers deposits, making it a complex production process. This multilayer coating increases reflectivity from the prism surfaces by acting as a distributed Bragg reflector. A well-designed multilayer dielectric coating can provide a reflectivity of over 99% across the visible light spectrum. This reflectivity is an improvement compared to either an aluminium mirror coating or silver mirror coating.


title: Binoculars

text: Porro prism and Perger prism binoculars and roof prism binoculars using the Abbe–Koenig roof prism do not use dielectric coatings because these prisms reflect with 100% reflectivity using total internal reflection in the prism rather than requiring a (dielectric) mirror coating.


title: Binoculars

text: The presence of optical high transmittance crown glass offering relatively low refractive index (≈1.52) and low dispersion (with Abbe numbers around 60) is typically denoted on binoculars by the following terms:


title: Binoculars

text: Hand-held binoculars range from small 3 × 10 Galilean opera glasses, used in theaters, to glasses with 7 to 12 times magnification and 30 to 50 mm diameter objectives for typical outdoor use.


title: Binoculars

text: Compact or pocket binoculars are small light binoculars suitable for daytime use. Most compact binoculars feature magnifications of 7× to 10×, and objective diameter sizes of a relatively modest 20 mm to 25 mm, resulting in small exit pupil sizes limiting low light suitability. Roof prim designs tend to be narrower and more compact than equivalent Porro prism designs. Thus, compact binoculars are mostly roof prism designs. The telescope tubes of compact binoculars can often be folded closely to each other to radically reduce the binocular's volume when not in use, for easy carriage and storage.


title: Binoculars

text: Many tourist attractions have installed pedestal-mounted, coin-operated binocular tower viewers to allow visitors to obtain a closer view of the attraction.


title: Binoculars

text: Although technology has surpassed using binoculars for data collection, historically these were advanced tools used by geographers and other geoscientists. Field glasses still today can provide visual aid when surveying large areas.


title: Binoculars

text: Birdwatching is a very popular hobby among nature and animal lovers; a binocular is their most basic tool because most human eyes cannot resolve sufficient detail to fully appreciate and/or study small birds. To be able to view birds in flight well rapid moving objects acquiring capability and depth of field are important. Typically, binoculars with a magnification of 8× to 10× are used, though many manufacturers produce models with 7× magnification for a wider field of view and increased depth of field. The other main consideration for birdwatching binoculars is the size of the objective that collects light. A larger (e.g. 40–45mm) objective works better in low light and for seeing into foliage, but also makes for a heavier binocular than a 30–35mm objective. Weight may not seem a primary consideration when first hefting a pair of binoculars, but birdwatching involves a lot of holding up the binoculars while standing in one place. Careful shopping is advised by the birdwatching community.


title: Binoculars

text: Hunters commonly use binoculars in the field as a way to observe distant game animals. Hunters most commonly use about 8× magnification binoculars with 40–45mm objectives to be able to find and observe game in low light conditions. European manufacturers produced and produce 7×42 binoculars with good low light performance without getting too bulky for mobile use like extended carrying/stalking and much bigger bulky 8×56 and 9×63 low-light binoculars optically optimized for excellent low light performance for more stationary hunting at dusk and night. For hunting binoculars optimized for observation in twilight, coatings are preferred that maximize light transmission in the wavelength range around 460-540 nm.


title: Binoculars

text: Some binoculars have a range finding reticle (scale) superimposed upon the view. This scale allows the distance to the object to be estimated if the object's height is known (or estimable). The common mariner 7×50 binoculars have these scales with the angle between marks equal to 5 mil. One mil is equivalent to the angle between the top and bottom of an object one meter in height at a distance of 1000 meters.


title: Binoculars

text: With the typical 5 mil scale (each mark is 5 mil), a lighthouse that is 3 marks high and known to be 120 meters tall is 8000 meters distant.


title: Binoculars

text: Binoculars have a long history of military use. Galilean designs were widely used up to the end of the 19th century when they gave way to porro prism types. Binoculars constructed for general military use tend to be more rugged than their civilian counterparts. They generally avoid fragile center focus arrangements in favor of independent focus, which also makes for easier, more effective weatherproofing. Prism sets in military binoculars may have redundant aluminized coatings on their prism sets to guarantee they don't lose their reflective qualities if they get wet.


title: Binoculars

text: One variant form was called "trench binoculars", a combination of binoculars and periscope, often used for artillery spotting purposes. It projected only a few inches above the parapet, thus keeping the viewer's head safely in the trench.


title: Binoculars

text: Military binoculars can and were also used as measuring and aiming devices, and can feature filters and (illuminated) reticles.


title: Binoculars

text: Military binoculars of the Cold War era were sometimes fitted with passive sensors that detected active IR emissions, while modern ones usually are fitted with filters blocking laser beams used as weapons. Further, binoculars designed for military usage may include a stadiametric reticle in one eyepiece in order to facilitate range estimation.


title: Binoculars

text: Modern binoculars designed for military usage can also feature laser rangefinders, compasses, and data exchange interfaces to send measurements to other peripheral devices.


title: Binoculars

text: Very large binocular naval rangefinders (up to 15 meters separation of the two objective lenses, weight 10 tons, for ranging World War II naval gun targets 25 km away) have been used, although late-20th century radar and laser range finding technology made this application mostly redundant.


title: Binoculars

text: There are binoculars designed specifically for civilian and military use under harsh environmental conditions at sea. Hand held models will be 5× to 8× magnification, but with very large prism sets combined with eyepieces designed to give generous eye relief. This optical combination prevents the image vignetting or going dark when the binoculars are pitching and vibrating relative to the viewer's eyes due to a vessel's motion.


title: Binoculars

text: Mariners also often deem an adequate low light performance of the optical combination important, explaining the many 7×50 hand held marine binoculars offerings featuring a large 7.14 mm exit pupil, which corresponds to the average pupil size of a youthful dark-adapted human eye in circumstances with no extraneous light.


title: Binoculars

text: Civilian and military ships can also use large, high-magnification binocular models with large objectives in fixed mountings.