Archived posting to the Leica Users Group, 2001/04/04
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Photoshop is very simple. It has a small number of concepts, and a small number of basic features. It then extends these with a gazillion variations and minor options, all of which make certain common operations easier and which are trivial to learn if you understand the conceptual model. In fact, it's so simple that I can explain it all right here in a message short enough to pass the LUG long-message filter. Photoshop reads files and puts them into its memory. In memory, it represents them as a stack of layers, in some color model. There are three things you can do with layers: 1. Select certain bits on a layer. Much of the complexity of photoshop is in the power tools that help you spend less time selecting the bits that you want to select. 2. Paint on a layer. There are many tools for setting paint color, texture, brush shape, etc. 3. Do systematic transformations to a layer. These save time, and permit geometric precision. You can rotate, scale, twist, search for dust, make brightness adjustments, and so forth. There are about 100 different things you can do to a layer, and most of them make sense and are quite intuititve. A few of them are hard to understand what they do if you don't have graphic arts experience. You can cut pieces out of one stack of layers and paste them into another. I believe that the reason why some people have trouble with Photoshop is that to use Photoshop you must know how to think about an electronic picture in terms of its representation. If you can look at the screen and comprehend what you are looking at as a stack of layers, each of which holds points in a certain color model, you'll be fine. Consider the tools palette in Photoshop. Starting at the upper left corner, I see Select*4, Move, Select*3, Select, Crop, Knife*2, Paint, Paint*2, Paint*2, Paint*2, Erase*3, Systematic paint*2, Blur, smudge, sharpen, dodge, burn, desaturate, Select*2, Write words, Paint*5, Paint*6, Annotate, Color measurement*3, Move, and zoom in. That summarizes to: Select: 10 Paint or erase: 21 Move or crop: 3 Darkroom stuff (dodge, burn, cut, blur, etc): 10 Systematic paint: 5 Bookkeeping: 2 Up on the top menubar there are some commands that control how to get pictures in and out, how to change shapes of pens and pencils and paintbrushes, how to change the color encoding, how to adjust the stack of layers, how to change what you are looking at, and then about 200 more systematic transformations, 10% of which are standard darkroom things like adjust contrast or adjust brightness. Photoshop 6 has a little more complexity because it knows how to store things that are not pictures, and you have to learn about them or learn how to ignore them. It can store geometric shapes (circles, rectangles, etc) and it can store text and fonts and instructions for what to do with them. There are a few places in Photoshop where you have to know some physics (the transfer curves), some graphic arts (rubylith and channel functions) or some mathematics (bezier curves). If you do know those things, then using them in Photoshop is very natural. If you do not know those things, the problem is not with photoshop but with your background. I think the reason that Photoshop has a reputation for being complex is that it's often the first place where people come across some of the hard problems in optics and photography and graphic arts. If you have never had to deal with the problems that rubylith solves, then you will probably find it mysterious when you first come across it. It's like when my children were studying Spanish, they came across, for the first time, grammatic constructs that they had not learned in their own language. They complained that Spanish was hard, but the real issue was that it was forcing them to learn concepts that they should have learned in English, and didn't. The part of Photoshop that it took me the longest time to learn was Alpha Channels. I still don't know where the idea came from or what problem they were trying to solve, and I know that if I ever learn that I will get a better understanding of Alpha Channels. Everything else is just bits, and tools for looking at them, changing them, and changing what they mean.