CMOS image sensor of the Nikon D90
The Nikon D40 is a DX-format camera. Here, the DX-sized image sensor is exposed.
Comparison of image sensor sizes, including Nikon DX.

The Nikon DX format is an alternative name used by Nikon corporation for APS-C image sensor format being approximately 24x16mm. Its dimensions are about 2⁄3 (29mm vs 43mm diagonal, approx.) those of the 35mm format. The format was created by Nikon for its digital SLR cameras, many of which are equipped with DX-sized sensors. DX format is very similar in size to sensors from Pentax, Sony and other camera manufacturers. All are referred to as APS-C, including the Canon cameras with a slightly smaller sensor.

Nikon has produced 23 F-mount lenses for the DX format, from macro to telephoto lenses. 35mm format lenses can also be used with DX format cameras, with additional advantages: less vignetting, less distortion and often better border sharpness. Disadvantages of 35mm lenses include generally higher weight and incompatible features such as autofocus with some lower-end DX cameras. Nikon has also produced digital SLRs that feature the larger Nikon FX format sensor that is the size of the 135 film format.

In 2013, Nikon introduced a high-end compact camera with a DX-sized sensor, the Nikon Coolpix A, featuring an 18.5mm lens.

In late 2019 Nikon announced their first Z-mount camera with an APS-C sensor, the Nikon Z50. This has been followed by an additional three DX cameras.

Implications

The 1⁄3 smaller diagonal size of the DX format amounts to a 1⁄3 narrower angle of view than would be achieved with the 135 film format (35mm film or FX format), using a lens of the same focal length. Strictly in angle-of-view terms, the effect is equivalent to increasing focal length by 50% on a 135 film camera, and so is often described as a 1.5x focal length multiplier.

This effect can be advantageous for telephoto and macro photography as it produces a tighter crop without the need to increase actual focal length. However it becomes disadvantageous for wide-angle photography as a wide-angle lens for 135 film effectively becomes a normal lens for the DX format (e.g. 28mm x 1.5= 42mm 135 film equiv.). This has led to the increased development of the DX format-specific lenses for the Nikon F-mount. Since these lenses do not need to cover the 135 film area, they are smaller and lighter than their 135 format counterparts of equal angle-of-view. The production of DX-specific lenses has also enabled the production of affordable wide-angle lenses for the format (e.g., 12mm), whereas costly ultra-wide-angle lenses from the 135 format were formerly required.

When DX format lenses are used on 135 format cameras, vignetting often occurs, as the image circle does not cover the entire area of the 135 format.

Vignetting produced by using a DX-format lens on a full-sized 35mm frame.

Active sensor size

Nikon uses DX format sensors with slightly different active areas, which is the area where the image is captured, although all of them are classified as APS-C. Image sensors always have additional pixels around the active pixels, called dummy pixels (unmasked, working pixels) and optical black pixels (pixels which are covered by a mask used as a black-level reference). The size differences are minuscule and not noticeable in practice:

MountCameraActive width (mm)Active height (mm)Horizontal pixelsVertical pixelsMP
FNikon D123.715.52,0121,3242.7
FNikon D1H23.715.52,0121,3242.7
FNikon D1X23.715.53,0081,9605.9
FNikon D2H23.715.52,4641,6324.2
FNikon D2Hs23.715.52,4641,6324.2
FNikon D2X23.715.74,2882,84812.3
FNikon D2Xs23.715.74,2882,84812.3
FNikon D4023.715.53,0082,0006.0
FNikon D40x23.715.63,8722,59210.1
FNikon D5023.715.53,0082,0006.0
FNikon D6023.615.83,8722,59210.1
FNikon D7023.715.53,0082,0006.0
FNikon D70s23.715.53,0082,0006.0
FNikon D8023.615.83,8722,59210.1
FNikon D9023.615.84,2882,84812.3
FNikon D10023.715.53,0082,0006.1
FNikon D20023.615.83,8722,59210.1
FNikon D30023.615.84,2882,84812.3
FNikon D300S23.615.84,2882,84812.3
FNikon D50023.515.75,5683,71220.9
FNikon D300023.615.83,8722,59210.1
FNikon D310023.115.44,6083,07214.2
FNikon D320023.215.46,0164,00024.0
FNikon D330023.515.66,0004,00024.0
FNikon D340023.515.66,0004,00024.0
FNikon D350023.515.66,0004,00024.0
FNikon D500023.615.84,2882,84812.3
FNikon D510023.615.64,9283,26416.2
FNikon D520023.515.66,0004,00024.0
FNikon D530023.515.66,0004,00024.0
FNikon D550023.515.66,0004,00024.0
FNikon D560023.515.66,0004,00024.0
FNikon D700023.615.64,9283,26416.2
FNikon D710023.515.66,0004,00024.1
FNikon D720023.515.66,0004,00024.2
FNikon D750023.515.75,5683,71220.9
Nikon Coolpix A23.615.74,9283,26416.2
ZNikon Z3023.515.75,5683,71220.9
ZNikon Z5023.515.75,5683,71220.9
ZNikon Z50II23.515.75,5683,71220.9
ZNikon Zfc23.515.75,5683,71220.9

Notes

Lenses

Nikkor DX lenses are marked with the DX logo.

F-mount Lenses for Nikon DX format

Current F-mount Vibration Reduction (VR) lenses in DX format

See also