A Guide to Full Frame
There is now more choice than ever before when it comes to sensor formats and cameras. Consideration in pre-production to which format to use is becoming even more important as the choice between not just which camera but which aspect ratio, resolution and sensor size is required.
Here, we're focusing on sensor size, and how it can affect your shoot.
What is Full Frame?
The standard television camera has had a massive overhaul in the past 13 years. From filming with traditional ENG cameras for broadcast, with a standard ergonomic shoulder mounted design and 2/3rd inch sensor or 16mm/35mm film for comercial, drama and features. Along came the Canon 5D MKII DSLR back in 2008. A literal game-changer. Full of pitfalls and disadvantages but it held one important feature; a full frame sensor. The 'filmic look' accidently became available to anyone.
The origins of full frame lie in Single Lens Reflex photography cameras or SLR's. A 35mm negative film measures 36x24mm. Super35mm became the standard with a smaller area of 24x14mm. Anything smaller than Full Frame is said to be cropped.
The Canon C300 MK1 debuted in 2011, a camera that was meant to be used for video, featuring a Super35mm sensor. Most video cameras will now shoot Super35 as a new standard for television requirements.
A camera's sensor size is the physical size of its image sensor, the width and height of which you usually measure in millimetres. It is therefore different from the number of pixels. However having a larger sensor allow the use of more pixels for higher resolution or bigger pixels to allow more senstivity to light.
Technology has advanced enough to allow digital video camera manufacturers to take the full frame concept used in still photography and apply it to their cameras, so that you can now shoot video in full frame.
Most full frame cameras have areas that measure around 36mm x 24mm with some differences being higher or wider depending on manufactuer.
Why Use a Full Frame Sensor?
There are distinctive benefits in using a larger sensor size:
It gives you more control over your depth of field.
An apparent wider angle of view.
More seperation between forground and background.
Improved low light performance.
Allow larger amount of pixels.
Allows greater proximity to actors without disortion.
A higher pixel count offers reduction of video noise.
Allows for a wider dynamic range with a full frame sensor.
Depth of Field Control
Using a full frame sensor, you can more easily achieve a shallow depth of field. This creates a greater seperation between foreground and background; directing the viewer's attention to a particular subject, or shift focus from one subject to another with a pronounced impact.
This is something you can do with a cropped sensor camera, by opening up the aperture and choosing a fast lens and moving closer to the subject but it's far easier with full frame.
This can have a negative impact when the camera or actors are moving, acheiving correct focus can become near unobtainable.
Good Low Light Performance
Because full frame sensors have a larger physcial size, pixel size can be increased allowing more light to be captured.
This can be crucial in shooting dark environments. You need less light in front of your camera to get the same exposure. Cameras like the Sony A7S MKIII and Canon ME-20F-SH both full frame and offer amazing 'see in the dark' sensors.
High Quality Close-ups
As full frame is a larger sensor size it allows for a larger optical circle through the lens, allowing for effectively a wider viewing angle with less distortion.
Shooting close-ups this way can expose more subtle details, while providing plenty of narrative content to them.
Noise Control and Resolution
The number of pixels in a sensor, and what size they are, play a vital part in determining the final quality of the material you shoot.
Typically, a camera with larger pixels will capture better quality images because higher pixels capture more detailed imageswith less video noise. This gives you cleaner images.
Wider Dynamic Range
The dynamic range is the difference between the details of darker shadows and the brightest highlights, under and over-exosure.
What the sensor can record depends on this dynamic range, and full frame sensors are better at capturing the full extent of a scene, including a range of shadows, midtones and highlights.
This means that when shooting landscapes, for instance, the wider dynamic range of full frame will capture details in both darker and lighter regions of the shot, making it more true to life.
Field of View and Sensor Size
Sensor size changes your field of view, but it is also determined by the focal length of the lens you are using.
For example, if you use a 50mm lens on a full frame camera, you will get a field of view of around 46°. But if you used the same lens on a camera with a smaller sensor, you would perhaps get a view of only 30°.
With close-ups, using a 50mm lens with a full frame sensor will only give you a medium-sized close up, but this would be much more extreme with a smaller sensor, even though the distance between camera and subject is the same.
This is what is known as the crop factor. It is something you should consider when shooting with full frame.
Lens Coverage for Full Frame
The image circle of a lens is the light or image that is projected out of its rear element, onto the camera's sensor.
The lens projects a circular image, which is seen as a rectangular image given the aspect ratio used.
You measure the diameter of this image circle in millimetres.
If you know this measurement, then you will know how large a sensor the lens can cover.
For example, to cover a full frame camera such as the Sony Venice, your image circle would need to be 46mm in diameter.
Lenses can cover sensor formats they were designed for, and smaller sizes of sensor. Usually, they cannot cover sensors that are larger than what they were intended to cover.
It is important to do your research about the compatibility of your lenses. If you choose lenses that don't work with the sensor size of your camera, then you will see a heavy vignette around the image or a port hole effect.
Why is Size Important for Aesthetic Quality?
If you're a filmmaker full frame expands your options. It enable you to deliver aesthetically superior content.
You can achieve a far shallower depth of field, separating your subject from its background and giving your footage more of a three-dimensional feel.
Using this larger format, you are not solely relying on wider focal lengths for your expanded field of view. This gives your camera a more natural perspective, which more closely resembles our own, human field of view.
Ultimately, though, it's about making the right choices to achieve the kind of finished visual impact that meets your objectives.