10 Basic Rules of Image Editing
Rule 1: If it looks good, then it’s fine (part 1)
Demystifying Image Editing
With Sagelight, one of my main goals is to demystify image editing. I mean, real, professional-level, artistically-expressive image editing.
To that end, I think that we tend to split image editing into two categories:1. Doing the simple, automatic things like getting rid of red-eye, bringing up the brightness, cropping, etc, but nothing that’s going to make our picture “pop” or otherwise fantastic.
2. Anything else, which suddenly becomes difficult and forbidding — “not for me!”
I remember when I first saw a computer. This was in the 70’s, when computers were still mysterious, and my father’s company was having an “open house” day. They had computers running the first Adventure Game, the first Star Trek Game (for those who remember the text-version of those — they were awesome), etc.
Nothing incredible by today’s standards, but amazing technology back then.
I remember my father saying to me, “Press a button… go ahead“. Right after I nervously pressed a button, my father exclaimed, “Oh my God! you broke the computer!“. That made me instantly afraid of computers for quite some time. I only figured out years later (like 30 years) that he was just kidding. Well, you’d have to know the dynamic between my father and myself to know why It took so long to understand that… moving on…
Oh, those were the days. Why do they have to grow up so fast?
The point is that computers became so mysterious because of the power they have by just pressing one button. I think the same can be true of image editing.
We all get that there is some sort of science behind it, if nothing else because people like me who write image editing programs remind us of this fact all the time, by using terms like “Gaussian Blur” and “Unsharp Mask“, not to mention “Exposure” (I mean, what is that?), “Gamma“, “Curves“, RAW, “demosaicing“, “histogram“, “equalization“, and so-forth, and so-forth.
It suddenly seems mysterious and, moreover, inaccessible.
Let me explain a few of these terms, and what they really mean:
- Gaussian Blur. All it really means is that someone like me is using an algorithm some guy wrote to blur your image. It’s incredibly difficult to write one that’s fast at all, but that’s my problem.
- Unsharp Mask. This is a term borrowed from photography. All it really means is that I blurred your image with a Gaussian Blur, subtracted the difference from the original image and tacked that difference right back onto your image. It’s a lot like that Laz Burhman song. The sliders simply control how much I blur, how much I subtract and how much I add back on. The bigger differences happen on edges, so when I add the difference back on, I’m adding more to the edges, hence the sharpening effect.
- Exposure. It means nothing. That’s why I personally don’t use the term in Sagelight. There’s no standard about what it means, and some editors use it differently than others. There is a trend in the industry to use technical terms to make it seem like we’re doing something more special than we are. In many editors for example “Exposure” just means “it’s brightening your image” (and killing the highlights in the process).
- Gamma. All it really means is that it’s brightening your image with a weight on the shadows. I’ll get ostracized in any industry publication for stating it that way, but that’s all it really amounts to in practical terms. It’s important to note that it’s standardized and used all over the place, like on your monitor. A standard curve for RAW files is to perform a curve on your image with a Gamma 2.2., so it’s nice to have a standard so the camera and I can know what to do with your image.
Well, I could go on. Of course, there are subleties to a lot of these terms that can make them more interesting (and powerful). But even for me — the author of an image editor — their practical application, at the image-editing level, is that my internal sense of a Gamma Curve (for example) is that it’s going to brighten my shadows more than the rest of the image. As much as I wish I was, I’m not one of those guys that can do the constant formula of some value to the power of 2.19383 in my head while I’m using a slider.
It’s a gut-sense that we get out of these things. That’s why it’s just really about experimenting with enough of a knowledge base to turn the trial-and-error approach into something that’s more intuitive down the road. This enables us to do more in expressing ourselves artistically and creatively — without having to know the science.
Part 2 coming soon…