APS-C

Advanced Photo System type-C (APS-C) is an image sensor format approximately equivalent in size to the Advanced Photo System film negative in its C ("Classic") format, of 25.1×16.7 mm, an aspect ratio of 3:2 and Ø 30.15 mm field diameter.

Most DSLR and third party lens manufacturers now make lenses specifically designed for APS-C cameras.

The designations by brand include: A crop factor (sometimes referred to as a "focal length multiplier" for comparing a proportionally scaled lens/image circle projection/sensor diameter) can be used to calculate the field of view in 35 mm terms from the actual focal length.

[21] These lenses place the rear of the lens closer to the camera's sensor (referred to as short back focus).

[citation needed] EF-S lenses will not physically mount on Canon's full-frame digital or 35mm film SLRs.

More recently, the company introduced the EF-M line for its EOS M series of mirrorless interchangeable-lens cameras (MILCs).

Canon sells an optional adapter that allows EF-M bodies to accept all EF and EF-S lenses.

The trademark compact design of the DA limited series takes advantage of the smaller APS-C format with the lenses under 40 mm and is fully usable on 135 Film with the DA Limited Lenses over 35 mm focal length.

The DT lenses can be mounted on any Sony A-mount camera, but are specifically designed for the DSLR-A100 up to DSLR-A700 series of APS-C-format DSLRs, the earlier Konica Minolta 5D and 7D, and the most recent APS-C Alpha SLTs.