Understanding Crop Factor in Photography

Crop factor is an important concept for photographers to understand, as it directly affects the focal length of a lens and how an image will appear in a photo. In this tutorial, we'll explain what crop factor is, why someone should know about it, and related topics to learn about in photography.

What is Crop Factor?

Crop factor is a term used in photography to describe the ratio of the size of a camera's imaging sensor to the size of a 35mm film frame. It is also sometimes referred to as a “focal length multiplier”. The crop factor is used to determine the effective focal length of a lens when used with a camera with a smaller sensor than a 35mm film frame.

Why is Crop Factor Important?

Crop factor is important because it affects the field of view of an image. A smaller sensor will have a smaller field of view than a larger sensor, and this can have a dramatic effect on how a photo appears. For example, a 50mm lens used on a full-frame camera will have a much wider field of view than the same lens used on a crop sensor camera. This is due to the fact that the crop sensor camera is using less of the image projected by the lens, resulting in a narrower field of view.

Crop factor is also important to consider when purchasing lenses. A full-frame lens used on a crop sensor camera will appear to have a longer focal length than it would on a full-frame camera. This can be either beneficial or detrimental, depending on the type of photography you are doing.

Related Topics in Photography

In addition to understanding crop factor, there are many other topics that a photographer should learn about in order to take better pictures. One important concept is understanding contrast in photography. Contrast is the difference between the light and dark areas in an image and can be used to create more dynamic and visually interesting photos. Understanding how to control and manipulate contrast can help a photographer create more aesthetically pleasing images. Other topics include understanding depth of field, shutter speed, white balance, and composition.

Summary

Crop factor is an important concept for photographers to understand, as it affects the field of view of an image and can have a dramatic impact on how a photo appears. It is also important to understand related topics in photography, such as contrast, depth of field, shutter speed, white balance, and composition. By understanding these concepts, a photographer can create better and more visually appealing images.

Here is a video on this topic:

video by Tony Northrup

Here is a spreadsheet with some common crop factors.

See Also:
Aspect Ratio
Photography Glossary