Nikon DX format

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The Nikon DX format is an image sensor format of approximately 24×16 mm. Its dimensions are about 2/3 those of the 135 film format (29mm vs 43mm diagonal, approx.). The format was created by Nikon for its digital SLR cameras, many of which are equipped with DX-sized sensors.

In 2007, Nikon announced the D3, featuring a full frame sensor known as the Nikon FX format.

[edit] Real sensor size

Nikon produces different DX format sensors of slightly different sizes.

Camera	Sensor width (mm)	Sensor height (mm)	Horizontal pixels	Vertical pixels
Nikon D2Xs	23.7	15.7	4,288	2,848
Nikon D2X	23.7	15.7	4,288	2,848
Nikon D2Hs	23.7	15.5	2,464	1,632
Nikon D2H	23.7	15.5	2,464	1,632
Nikon D1X	23.7	15.5	4,024	1,324
Nikon D1H	23.7	15.5	2,012	1,324
Nikon D1	23.7	15.5	2,012	1,324
Nikon D300	23.6	15.8	4,288	2,848
Nikon D200	23.6	15.8	3,872	2,592
Nikon D100	23.7	15.5	3,008	2,000
Nikon D80	23.6	15.8	3,872	2,592
Nikon D70s	23.7	15.5	3,008	2,000
Nikon D70	23.7	15.5	3,008	2,000
Nikon D60	23.6	15.8	3,872	2,592
Nikon D50	23.7	15.5	3,008	2,000
Nikon D40x	23.7	15.6	3,872	2,592
Nikon D40	23.7	15.5	3,008	2,000

[edit] 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, 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 1.5× 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 and sacrifice depth of field. However it becomes disadvantageous for wide angle photography as a wide angle lens for 135 film (e.g., 28mm) effectively becomes a normal lens for the DX format (28mm × 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 film cameras, vignetting often occurs, as the image circle doesn't cover the entire area of the 135 film.