What is crop factor in photography?

What is Crop Factor? Crop factor is one of the most useful concepts in modern photography, and one of the most consistently misunderstood. Whether you are choosing your first interchangeable-lens camera, comparing systems, or trying to work out why a 35mm lens looks different on two different cameras, understanding crop factor is the key to making informed decisions about gear and getting the framing you actually want. This guide explains what crop factor is, why it matters, and how it works across the full range of sensor sizes available in today’s cameras, from compact 1-inch sensors all the way up to medium format. What is crop factor? Crop factor is the ratio of a camera’s sensor size to the standard 35mm film frame, which measures 36 x 24mm. The term dates from the long history of 35mm film, which became the dominant photographic format throughout the twentieth century. Even today,...