How a Camera Works

The camera is the beating heart of photography. This is the device where the magic happens — where light is captured and imprisoned, by chemical or electrical means. If you want to master photography, the camera is the essential place to start.

A Rolleiflex 3.5 camera, from the 1950s. Photo by Ardi Evans on Unsplash

There are many different types of camera. All essentially capture light, but, since the invention of the first photographic devices more than 150 years ago, countless different techniques for doing so have been developed. Nowadays most cameras are digital, and most serious photographers will have either a DSLR camera or a mirrorless camera.

Here we’ll cover those two types of camera. But don’t give up if you have another type of camera, even if it’s just a phone camera. The basic principles of the camera hold for most modern devices, and all photographers can benefit from understanding them.

There are two main parts to all cameras — an optical part, that manipulates light, and a chemical or electrical part, that captures light. Today most cameras use electrical methods to capture light, with chemical means relegated to older analogue cameras. Here, then, we’ll focus on the electrical ways of recording light.

The Basics

The image below shows a DSLR camera, a common type of digital camera. In the last few years mirrorless cameras have also become widespread, but the…