APS-C

The Canon EOS 60D, a typical APS-C format camera

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.

CCD Sony ICX493AQA 10.14(Gross 10.75) Mpixels APS-C 1.8" (23.98 x 16.41mm) sensor side

Sensors approximating these dimensions are used in many digital single-lens reflex cameras (DSLRs), Mirrorless interchangeable-lens cameras (DSLMs), and a few large-sensor live-preview digital cameras. These include the Sony DSC-R1, Sigma DP1 and Leica X1. APS-C size sensors are also used in a few digital rangefinders (e.g., the Epson R-D1).

Such sensors exist in many different variants depending on the manufacturer and camera model.^[1] 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". Sensor sizes range from 20.7×13.8 mm to 28.7×19.1 mm. 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.

Comparison with other formats

Using the same resolution, the quality of the image from an APS-C sensor is higher (especially in low-light scenarios) when compared to a smaller sensor, due to its pixels having a larger size which allows it to collect more light. Alternatively, an APS-C sensor could have higher resolution and maintain the same image quality as a camera with a proportionately smaller sensor.

However, compared to a full-frame camera, image quality is lower, particularly at high ISO values (shooting with little light).

Also, geometric distortions (near the picture edges in particular) may decrease with a smaller sensor.

Brand designations

Drawing showing the relative sizes of sensors used in most current digital cameras.

Most DSLR and third party lens manufacturers now make lenses specifically designed for APS-C cameras. The designations by brand include:

• Canon: EF-S, EF-M
• Konica Minolta: DT
• Nikon: DX
• Pentax: DA
• Samsung: NX
• Sigma: DC
• Sony: DT, E
• Tamron: Di II
• Tokina: DX

Multiplier factors

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 35 mm equivalent focal length from the actual focal length. The most common multiplier ratios:

• 1.7× — Sigma DP1, Sigma DP2, Sigma SD15, Sigma SD14, Sigma SD10, Sigma SD9, Canon EOS DCS 3^†
• 1.62× — Canon EOS 7D^†, 7D Mark II. 50D^†, 60D, 70D, 550D (T2i)^†, 600D (T3i/X5), 650D (T4i/X6i)^†, 700D (T5i/X7i), 750D (T6i/X8i), 760D (T6s/8000D), 1100D (T3/X50)^†, 1200D (T5/X70); Canon EOS M, M2 (sold in Asia only), M3 (not sold in North America)
• 1.56× — Nikon D3100^†[2]
• 1.55× - Sony Alpha 58,^[3] Nikon D3200^†[4]
• 1.54× — Pentax K20D,^†[5] Samsung NX5^†, Samsung NX10^†, Samsung NX11^†, Samsung NX100^†,^[6] Sony NEX-5†^[7]
• 1.53× — Pentax K-3,^[8] K-S1,^[9] K-S2, K-5 II^†, K-5^†, K10D^†, K200D^†, Ricoh GR,^[10] Nikon D3300, Nikon D5300, Nikon Coolpix A,^[11] Sony NEX-7,†^[12] Sony NEX-6,^[13] Sony Alpha ILCE-6000,^[14] Sony Alpha 77, Sony Alpha 77 II, Sony Alpha 65, Sony Alpha 57, Sony Alpha 37, Sony Alpha 580, Sony Alpha 500, all Samsung NX except NX5, NX10, NX11, NX100
• 1.52× — All Nikon DX format DSLR cameras except D3100, D3200, D3300, and D5300; Pentax K-30^†, K-01,^[15] K-50,^[16] K-500;^† all Fujifilm interchangeable lens X-system cameras and X100 series; Sony Alpha 100;^[17] Sigma SD1, Sigma SD1 Merrill, Sigma DP1 Merrill, Sigma DP2 Merrill
• 1.3×^‡ — Canon EOS-1D Mark IV^†, 1D Mark III^†, 1D Mark II^† (and Mark II N), EOS-1D^†, Kodak DCS 460^†, DCS 560^†, DCS 660^†, DCS 760^†, Leica M8, M8.2

Notes:

^†Discontinued

^‡ A 1.3× Focal Length Multiplier is also known as APS-H. Actual multiplier factor is 1.255x for the 1D Digital, 1.28× for the Canon EOS-1D Mark III and 1.29× for the Canon EOS-1D Mark IV. Leica M8 is 1.33x

APS-C lens formats

Canon, Nikon, Pentax and Sony have developed and designed lenses specifically for their cameras with a lens factor (more fully, lens focal length conversion factor) or "crop factor" with most of the brands use 1.5× crop factor, except Canon use 1.6× crop factor. APS-C cameras use a smaller area to form the image than traditional 35 mm cameras, and so lenses used on APS-C format cameras have a correspondingly narrower field of view. For example, a 28 mm lens is a wide angle lens on a traditional 35mm camera. But the same lens on an APS-C camera, with a lens factor of 1.6× (relative to a standard full-frame 35mm format camera), has the same angle of view as a 45 mm (28 mm × 1.6 lens factor) lens on a 35 mm camera—i.e. a normal lens.^[18] Several third-party lens manufacturers, such as Tamron, Tokina, and Sigma, also manufacture a range of lenses optimised for APS-C sensors.

Canon introduced the Canon EF-S line of lenses in 2003 alongside the 300D. These lenses place the rear of the lens closer to the camera's sensor (referred to as short back focus). This has several benefits, including lighter lenses and a narrower field of view (which implies “longer” zoom). EF-S lenses are compatible with Canon's APS-C digital SLRs, with the exception of the early Canon EOS D30, Canon EOS D60, and Canon EOS 10D, which predated the introduction of the mounting system. EF-S lenses will not physically mount on Canon's full-frame digital or 35mm film SLRs.

Nikon makes DX format lenses for their line of APS-C digital cameras. These can be physically mounted to all Nikon digital and film SLR camera bodies since 1977. These lenses generally exhibit vignetting at shorter focal lengths when mounted on Nikon FX (full-frame) digital, or film bodies, but are typically usable at longer focal lengths.

Pentax produces the DA line for their APS-C cameras (the company has yet to introduce a full-frame DSLR). These lenses are available in focal lengths that offer similar field-of-view as lenses previously available for 135 film. The trademark compact design of the DA limited series takes advantage of the smaller APS-C format with the lenses under 40mm and is fully usable on 135 Film with the DA Limited Lenses over 35mm focal length. All DA lenses can be mounted on Pentax film bodies, albeit with increased vignetting. All fixed focal lengths in the rugged DA* series cover 35 film format fully.^[19]

Sony has a DT line specifically designed for their APS-C cameras. These 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 current Alpha SLTs. DT lenses can be mounted on full-frame models like the DSLR-A850, DSLR-A900, SLT-A99, or A7/A7R in "crop" mode, where the frame is cropped and the resolution is roughly halved.

See also

• 35 mm equivalent focal length
• Advanced Photo System
• Crop factor
• Digital versus film photography
• Film format
• Full-frame digital SLR
• Image sensor format
• Image sensor
• Lenses for SLR and DSLR cameras
• List of large sensor interchangeable-lens video cameras

References

External links

• Bob Atkins: The Future of Digital - Full Frame or APS-C? written in 2004
• Vincent Bockaert: Focal Length Multiplier Digital Photography Review, written in 1998
• Fred Kamphues: The digital crop factor explained, written in 2005
• Zack Smith: SSensor Pixel Size as a Determinant of Digital Camera Image Quality, written in 2007