APS-H

Advanced Photo System type-C (APS-C) is an image sensor format approximately equivalent in size to the Advanced Photo System "classic" negatives of 25.1×16.7 mm, an aspect ratio of 3:2.

Sensors approximating these dimensions are used in many digital single-lens reflex cameras (DSLRs), Mirrorless interchangeable-lens cameras (MILCs), and a few large-sensor live-preview digital cameras. APS-C size sensors are also used in a few digital rangefinders.

Such sensors exist in many different variants depending on the manufacturer and camera model. All APS-C variants are considerably smaller than 35 mm standard film which measures 36×24 mm. Because of this, devices with APS-C sensors are known as "cropped frame", especially when used in connection with lens mounts that are also used with sensors the size of 35 mm film: only part of the image produced by the lens is captured by the APS-C size sensor. Sensor sizes range from 20.7×13.8 mm to 28.7×19.1 mm, but are typically about 22.5×15 mm for Canon and 24×16 mm for other manufacturers. Each variant results in a slightly different angle of view from lenses at the same focal length and overall a much narrower angle of view compared to 35 mm film. This is why each manufacturer offers a range of lenses designed for its format.

The quality of the image from an APS-C sensor is higher when compared to a smaller sensor due to its larger size which allows it to collect more light. However, compared to a full-frame camera, image quality is lower, particularly at high ISO values (shooting with low light).

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", even though the actual focal length is the same) can be used to calculate the field of view in 35 mm terms from the actual focal length. The most common multiplier ratios:

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