Nikon DX format

DX format is Nikon's name for its APS-C format system. For example, both D200 and D80 are called DX format cameras, and the lens with DX in it is named as the lens suitable for this system.

What is APS-C format:

We usually refer to the size of 135 film as 36×24mm Quan Huafu, and APS (Advanced Photographic System) is an outdated photographic system. There are three sizes of APS film: H, C and P. APS-H is Quan Huafu (30.3× 16.6 mm), and APS-C is cut off at the left and right ends of Quan Huafu with an aspect ratio of 3:2, which is about (24.0× 16.0 mm). APS-P has one truncation above and below Quan Huafu, so the aspect ratio of the picture is 3: 65438.

Digital SLR borrows this standard, and 22.5 x 15.0 mm, 23.6 x 15.8 mm, 23.7x15.6mm and 22.2x14.8mm whose CCD size is close to APS-C are called APS-C frames.

The 28.7x1mm of EOS- 1D and 1DMkII are called APS-H frames.

You can also use 1.0 times1.3 times1.5 times1.6 times, that is, the multiple of Quan Huafu diagonal size and system diagonal size, to indirectly represent the frame, that is, the focal length conversion coefficient.