How do Digital Cameras work?
I know a bit about digital cameras, but I have a few questions that I would really love to kno the answers to:
1.) If camera sensors only sense red, green, and blue, then how do they pick up colors like yellow and orange? I know about how additive color works, but, for example, in a 3 chip design with a prism that separates the incoming light only into red, green and blue, sending those to dedicated sensors that only pick up red, green, or blue, what happens to the yellow and orange, how are those colors picked up if they’re not even split by the prism?
2.) Why is it that cheap camcorders often have high levels of optical zoom (78X on one model I saw), while more expensive models generally only have 20X and below optical zoom?
First guy answered your second question, so there’s no need to go over that again.
As for the first, look at this.
http://thelightroomlab.com/2010/11/understanding-digital-camera-color-space-choices/
This is a color space for digital cameras. The reason we use rgb and not yrb like we do with painting is painting is based on our eye’s perception of light and how colors mix. in reality, wavelengths of light are more geared towards green, blue and red as being prime colors and cyan, magenta, and yellow as the absence on one of those colors. Magenta or purple is created by the lack of green in a picture, thus red and blue mix together to make magenta, if a little green is added, the color shifts a bit towards the green on the color space.
Cyan is the same, it’s the lack of red in a blue green mix that creates cyan, we add some red and the color again shifts just a bit.
Black is of course the absence of all three colors, and white is when there is a perfect color balance between the three.
To answer your question, the sensors on your camera evaluate how much red, blue and green are hitting them at any given point, then the camera does some very tricky algorithms to determine the color balance, if there is no blue detected and there is an equal amount of green and red, then yellow is the color, if no blue is detected and there is a shift towards the red spectrum over the green, then orange is the color selected, this all happens on the pixel level, for each pixel there are 3 sensors, each one gathering either the red blue or green shift, at the pixel level this doesn’t seem to add up to much, but just like the art style of pointillism one dot of color surrounded in a sea of dots, will create an image, if your number of dots reach into the millions like they do on today’s modern cameras then you have a true to life representation of what you saw, fo the most part.
Hope this helps
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