I'm working on a project and I have a quick question...which purple color scheme do you think I should go with; The lighter one surrounded by black on the left, or the slightly darker purples surrounded by white on the right?
Even if you're color blind you probably already failed the first question. Why? Well our eyes see lightness relative to the surrounding ambient. The purple boxes are exactly the same left to right. I stole this image from Billy Biggs page talking about chromatic adaptation. I think this issue comes up for me most often when I prepare an image on the computer, think it's perfect, then print it and find out that the print is too dark. It's all relative to your display environment. Yes kids, this is a science lesson, but a valuable one.
Subconsciously I think we all develop a picture in our head a split second before taking a photo - the saturation, the hues, the contrast... Does it ever match reality? Hardly ever. Now at least we have a good excuse that doesn't involve the camera performance. Different environment, different viewing results.
Second question. What is the opposite of purple? Before reading on stare at the purple square in the center below for one minute, then look to the white area to the right. The answer will reveal itself.
This is another case of chromatic adaptation. When you look at the purple long enough your eyes adjust to somewhat counteract that stimulus. What you should see in the center when you look away from the color blocks (with a white background) is green. I found this example on the HP labs web site from a paper published by Nathan Moroney titled "The Opposite of Green is Purple?".
So looking at an image for an extended period of time changes how we perceive the image. Another science lesson. That's all for today. No homework scheduled.