Gollnick, are you saying that the manual white balance setting in my camera will result in less detail then getting the right lamps? I dont do much photography but always trying to learn.
Yes. This is because adding offsets to compensate for bad light eats into the dynamic range of the signal (the color) you're trying to measure. Less dynamic range means less color depth and that means less detail. And detail on edges is what gives the appearance of sharp focus.
By the way, the same thing happens if you try to adjust color balance using editting software such as Photoshop.
There's an old saying that describes most physical systems: There's no such thing as a free lunch. In other words, no benefit in one place comes without a cost somewhere else. When we claim the benefit of correcting for bad light, we have to pay a cost somewhere else.
There's another old saying about computers (and digital photography fall into that realm): garbage in, garbage out.
Poor light in gives poor light out.
It is often helpful to do what Einstein called a "Gedankenexperiment," a thought experiment. One way to do this is a "reductio ad absurdum" experiment. Reductio ad absurdum means "reduce to the absurd. In this case, let's take something completely to extreme. To mix Latin and German, a reductio ad absurdum gedankenexperiment.
Let's imagine taking a picture with perfectly white light. Our subject is a mirror-polished blade. The colors in the picture will be perfect. The blade will appear bright silver.
Now, let's imagine taking this same picture with a pure red light. What will the picture look like? The polished blade will reflect back the red light and appear red in the picture, not silver.
This is absurd to think of purely red light, but what our simple thought experiment shows us is that if the light coming into a scene is wrong, then the picture taken of that scene will be wrong. Imagine trying to fix it in Photoshop. There simply is no green or blue information. Anything you can persuade photoshop to add in is just noise and will make the image worse.
What if we go back to our laboratory of the mind and make a new light source. This one is 50% red, 25% blue, and 25% green. The picture taken under this light source is still not right. But at least it has some blue and green in it. So, if we take it to Photoshop, maybe we can fix it.
We could fix it by lowering the red level by 50%. But if you did that, you'd loose detail in the red channel. You would be essentially trying to squash ten pounds of information into a five pound sack. Something has to be left out. And what gets left out is the detail in the information (you can prove this to yourself by playing some complex music on your stero at a comfortable level. Turn the volume down by half and you will see that you can hear less detail, less complexity in the music.)
The other way to fix it is to raise the green and blue channels 200% each. But when you do that, you'll not only amplify the signal, but the noise along with it. And the resulting noise covers up detail. Essentially, you are now trying to stretch 5 pounds of information to fill a ten pound container. Something has to be added. And what gets added to fill the space is noise.
The same sort of thing goes on inside your digital camera when you press the white balance button. The whilte balance button on your camera and the color balance menu in your photo editting software basically do the same thing.
The best solution is to take your picture with light that is 33 1/3% red, 33 1/3% green, and 33 1/3% blue and then not dicker around with either the white balance on your camera or the color balance controls in your photo editting software.
