Where is Lensk located?
Yakutsk Yakutsk (Russian: Якутск ; ] ; Yakut: Дьокуускай , "D'okuuskay", ] ) is the capital city of the Sakha Republic, Russia, located about 450 km south of the Arctic Circle. Population:  (2010 Census) ;  (2002 Census) ;  (1989 Census)
Pentax K-mount The Pentax K-mount, sometimes referred to as the "PK-mount", is a bayonet lens mount standard for mounting interchangeable photographic lenses to 35 mm single-lens reflex (SLR) cameras. It was created by Pentax in 1975, and has since been used by all Pentax 35 mm and digital SLRs (with the exception of the medium format 645D and 645z), as well as the MILC Pentax K-01. A number of other manufacturers have also produced many K-mount lenses and K-mount cameras.