How does a camera work?

It's incredible how a device in your pocket can freeze a split second of reality forever. To tailor our journey into the physics and magic of how cameras capture the world, I'd love to know what's drawing you to this topic today.

I want to improve my photography skills with a DSLR or phone

That's a fantastic starting point because both devices actually rely on the exact same fundamental principles of physics to capture an image. To help us dive into how they do this, are you currently using a smartphone camera, a DSLR/mirrorless camera, or both?

I use my smartphone camera

It's wonderful that you primarily use your smartphone camera, as modern phones pack some of the most sophisticated computational photography technology in existence! To understand how they do this, we need to start with the most basic element of photography: light itself.

The Journey of Light

Every photograph you take starts with light bouncing off objects in the environment. When you look at a scene, you aren't seeing the objects themselves; you are seeing the light rays that have struck those objects and reflected into your eyes. In the exact same way, a camera works by capturing these reflected light rays. These rays of light travel in straight lines through the air, carrying the color and brightness information of whatever they just bounced off of.

Light rays from a sun strike a tree and reflect into a camera lens.

Because light travels in straight, chaotic lines in every direction, a camera needs a way to organize this scattered light. Without a way to gather and organize these rays, the camera would just record a blurry, unrecognizable smear of light. That's where the lens comes in. Its main job is to redirect those bouncing light rays so that they neatly converge, allowing us to form a crisp, clear image.