The difference between SLR frames

Full frame

The so-called full frame refers to the size of traditional 135 film. The traditional camera film size is 35mm, 35mm is the width of the film (including the perforations), and the photosensitive area of ??35mm film is 36 x 24mm. The size of the CCD (or CMOS photosensitive imaging element) of a digital SLR is the same as the size of 135 film, 36 x 24mm, which is called "full frame".

Non-full-frame-APS

The APS system jointly developed by FujiFilm, Kodak, Canon, Minolta, and Nikon was launched in 1996. APS is the abbreviation of "Advance Photo System", which is translated as: "APS advanced photography system" in China. APS developers have made thorough improvements based on the original 135 specifications, including comprehensive innovations in cameras, photosensitive materials, printing equipment and related supporting products. They have greatly reduced the size of the film, used a new smart cassette design, and integrated contemporary The latest digital technology has become a smart film that can record optical information and digital information.

APS is positioned in the amateur consumer market. Completely different from the frame format of the 135 system, *** has designed three film formats (H, C, P):

H type is full frame (30.3×16.6mm), with an aspect ratio of 16 :9;

Type C blocks one end of the left and right ends of the full frame, with an aspect ratio of 3:2 (24.9×16.6mm), the same ratio as the 135 film;

P type is a full frame with one strip on the top and bottom blocked off, so that the aspect ratio of the screen is 3:1 (30.3×10.1mm), which is called panoramic mode.

In digital SLR cameras, most of them use CCD or CMOS photosensitive devices with a size smaller than 135. Except for Olympus’ 4/3 system and Canon’s full-frame, almost all of them are APS- C-type film is approximately the same size, so people call this size of photosensitive device "APS-C specification". Vignetting is less likely to occur in non-full-frame images at large apertures, but vignetting may occur in full-frame images. The main reason is the lens. The larger the field of view, the light condensing effect of the lens causes weak peripheral light and vignetting. The non-full-frame photosensitive area is small and the bright light area in the center is intensively used, so vignetting is less likely to appear than in the full-frame photo.