What is Crop Factor?

Understand the terms crop factor and full size sensor will help you when you are considering digital camera or lens options.

Before the advent of digital cameras and digital sensors, camera and lens manufactures made their cameras to work with 35mm film. It was the most popular and most widely used format in photography for many years.

It was easy to compare different camera lenses, their focal lengths and their zoom ranges. A 50 mm lens was considered "normal" and longer lens were considered telephoto. Shorter lenses were considered to be wide-angle.

Now digital cameras can be made without a full size sensor-which is the same size as a 35 mm film "negative."

The illustration above show you what would happen if you used the same lens on cameras having smaller than full frame sensors. A "crop factor" means that your photograph would have a smaller field of view. In other words, it crops part of the photograph that the lens is capable of including in your photo.

As a result – when you fit a lens to a camera with a smaller sensor the lens is often said to have a larger equivalent lens size.

Look at the 2 highlighted spots in the chart above. Using a 50 mm lens on a camera with a full size sensor would give you the effect of using an 80 mm lens by using that same lens on a camera with a 1.6 factor sensor.

That lens would be "normal" on a full size sensor camera and would be a telephoto lens on the camera with the smaller sensor.

To see examples of this, take a quick peak at the photos in this article on lens comparison: Camera Lens Comparison

Back from Crop Factor to Digital Camera Instructions