Aspect Ratio

The aspect ratio is the relationship between an image's height and width. Aspect ratios are more often written with the width first, followed by the height. The aspect ratio you use depends on the type of project you're shooting. It is usually recommend to use 4:3 for photos and 16:9 for videos.

A 3:2 aspect ratio is used by 35mm crop-sensor and full-frame DSLRs, some Leica medium format cameras, most mirrorless cameras, high-end compact cameras, and most 35mm film cameras.

The 4:3 aspect ratio is used by Micro Four Thirds cameras, many compact cameras, some medium format digital cameras, as well as medium format film cameras using the 6 cm x 4.5 cm format.