Monday, October 7, 2013

Digital Imaging (Part I)

In the above image from Top Right moving clockwise are three illustration that I would like to talk briefly about the first is a drawing of the different layers which are contained with in a digital imaging sensor the second is a lesser detailed image but the one with which I will be talking about to help simplify the way the sensor works. The third and bottom image is a actual sensor as a whole.

What is most interesting in the way that the sensor has evolved can be seen in the far right image. Take notice to the four layers, Red, Green, Blue, and then the Sensor. Focus on the squares, each square represents a pixel, the amount of pixels or squares on the sensor results in the detail of the final image, more squares being more detail, and the possibility of producing a larger final image.

What about the layers? To better understand how the image is produced lets go back and talk for a moment about how the original digital sensors(not pictured) where different, they being comprised of only two layers, the image sensor underneath and the color sensor above. The color sensor use to look like a checker board, one made out of three colors, a red square then a blue one then a green one.

Why the colors? Each color sensor filters out only that particular color. Think about this like a pair of sunglasses filters out the harsh UV rays but still allowing enough of  the light to still come through so we can still see.  

How does that information help? Because now that the sensor is layered it can record all at once each amount of color in the image on each square, instead of only a red color once every four squares, then a blue, and so on. This results in a much larger and more detailed image, it also allows for more accurate post processing. 

Tomorrow we'll take a less technical look at the process and I will post some examples of different gear, and a camera that cost more than a Cadillac!

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