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This Page is a Fantastic Primer on How Cameras and Lenses Work


If you want to learn the science and technical details of how cameras and lenses work, there’s a fantastic new resource on the Web for you. Developer Bartosz Ciechanowski has published an interactive 5,700-word article that explains things in great depth.

“Pictures have always been a meaningful part of the human experience,” Ciechanowski writes. “From the first cave drawings, to sketches and paintings, to modern photography, we’ve mastered the art of recording what we see.

“Cameras and the lenses inside them may seem a little mystifying. In this blog post I’d like to explain not only how they work, but also how adjusting a few tunable parameters can produce fairly different results.

“Over the course of this article we’ll build a simple camera from first principles.”

Ciechanowski first explains how light is recorded by image sensors, including how photons detected through a color filter array are turned into color images through demosaicing.

The article walks through the basics of a simple pinhole camera and uses interactive sliders to show how changing the size and distance of the aperture affects the resulting image.

The article even goes into classical electromagnetism and wave propagation.

The interactive illustrations Ciechanowski created are among the best we’ve seen in articles of this type.

By the end, you should have a fairly thorough grasp of what exactly is going on when you do things like adjusting your aperture for a wider or narrower depth of field.

“We’ve barely scratched the surface of optics and camera lens design, but even the most complex systems end up serving the same purpose: to tell light where to go,” Ciechanowski writes in conclusion. “In some sense optical engineering is all about taming the nature of light.

“The simple act of pressing the shutter button in a camera app on a smartphone or on the body of a high-end DSLR is effortless, but it’s at this moment when, through carefully guided rays hitting an array of photodetectors, we immortalize reality by painting with light.”

Head on over to Ciechanowski’s article to give it a read, but be warned: you may come out the other end a whole lot more knowledgeable.

Thanks to Ted Kinsman for sending in this tip!