How does photography work? How do you take a moment in front of you and put it on paper and keep it forever?
In: Technology
Do you remember when the eclipse was approaching and cheap people were making [eclipse viewers](https://en.wikipedia.org/wiki/Camera_obscura) with a box and a piece of foil with a hole poked through it? Those worked by projecting the sun on the inside of the box, allowing a safe view of the crescent sun.
They work because when light passes through a small enough hole, all the light moving in any direction can only go to one spot on the back of the box, so it creates a clear image. Cameras use the same principle (the earliest cameras used a pinhole), modern cameras use a lens that lets more light through but projects in the same way.
To capture the image the camera either it uses chemicals (silver salts) that change color in response to light, or it uses tiny solar cells each covered by a color filter that blocks out almost all light that isn’t Red, Green, or Blue. Then the voltage generated is measured which indicates the how much light entered or how bright that color was.
We use other chemicals to stop the silver from reacting to light (this needs to be done in the dark), or software to reassemble the data captured into an image that can be viewed on an electronic device or printed.
Latest Answers