Sunday, February 17, 2013

RGB and a slow decline from sanity

Oh, whats up, dear readers? Truly, this blog is in a rough patch. Im back to the old and sloppy schedule of one entry per week, and whoah, isnt that just disappointing. And its not like my material is any better, either. The january-low is over, but now its like uninsipred-february instead, wtf is that all about.

You know, something ive been wondering about for a while now is how does my art look on someone elses PC? I mean, PC monitors arent pictures, they represent pictures. The problem is, 2 representations of the same picture may not look the same. For example, your screen may have different gamma settings, or different colour warmth, or different contrast settings. Or faults. Before, Ive never used pure white in a gradiented shading, because pure white was an artifact on my screen. You guys wouldnt have noticed the difference, though, because pure white looks just fine on your screens.

Oh, LCDs. Thats what most of us use. I recently got a new PC screen, thats why I decided to write about it. Perhaps the most interesting thing about LCD screens, is that none of the colours are real. Except for a specific wavelength of red, green, and blue. All the other colours, like yellow, or anything that can be created by mixing RBG colour space, are fake.

How a simple LCD pixel works, is that it alternates from blocking out and letting through specific wavelengths of light. The LCD in your PC works by shining a white light as backlight (White light contains every wavelenght of visible light.), and then having one filter block out red light, another filter block out green light, and a third one to block out blue light, and it does this for each and every pixel individually. The result is a mix of Red, Blue and Green light. We call this RGB colourspace. RGB is special, because the brain can mix red, blue and green to emulate just about any colour visible to the human eye.

What this means, is, that when you think you see Cyan on your PC screen, you actually dont. The RGB filter blocks out red wavelengths, leaving us with Green and Blue. To the brain, this is indistinguishable from Cyan, even though there are no cyan wavelengths hitting your retina. Green and blue mix together, and that creates the illusion of Cyan.

If you took a macroscopic photograph of your PC screen, you would be able to make out what is called subpixels in your screen. These subpixels are red, blue and green pixels that all exist within the space of one pixel. Looking at them individually, you would never know they together created Cyan, you would view them as 2, Green and Blue, dots. But because you cant normally make them out individually, they meld together in your vision, and then the Cyan illusion is created.

I hope that made you smarter.



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