Archived posting to the Leica Users Group, 2006/03/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> Gary - any chance you can share cheat sheets - i know it's cheating > but so long as the teacher doesn't see us ..... > > ernie nitka > > photoshop challenged in Denver OK, Scott and Ernie and whoever else is interested. Here is the "cheat-sheet" I mentioned earlier for getting Photoshop (PS) to behave like a darkroom regarding the concept of dodging and burning. The basic idea in PS is that an "adjustment layer" (AL) lets through a PS effect (brightness, contrast change, color saturation adjustment, etc) wherever the AL is white. That same effect is blocked wherever the AL is black. An AL itself is ONLY black and white and shades of gray. Creating the gray portions of an AL lets a part of the effect into the appearance of the photo. That gray-softened border in the AL is like the darkroom technique of moving your hands or dodging tool continually to avoid an abrupt edge on the print where you have modified the exposure. There are a dozen different ways to do anything in PS. This technique keeps file sizes smaller than duplicate layers of the Background and, once learned, works rather quickly. The following instructions assume some knowledge of PS already and won't make much sense to a beginner. Many local classes are usually available for beginning PS, which is like showing you where the brake, gas pedal and steering wheel are. You might get of the driveway OK. But if you're comfortable out on the PS street, then let's hit the freeway: What follows is not casual reading, unless you like cookbooks. It's more of a "lab" session, so you'll probably want to print out the directions for reference as you do each part of the lesson while in PS. 1. Start Photoshop and open a digital photo file that could be improved by what you would normally accomplish in the darkroom through some simple dodging and burning. A good example might be a backlit face that is too dark. 2. Use the Lasso tool to select an area that you want to brighten up. (Tools palette, click and hold the Lasso box to get the three types of Lasso's to display. Pick the one that has the angles on it, but not the angled one with the little dots - it is probably the one already "remembered" by PS). 3. Make a rough outline with the lasso tool around the area you want to dodge or burn. (Click, drag to the next spot, let go, click again and drag again, eventually clicking back to where your started, thereby completing the "polygon" around your dodge/burn area). Don't try to be exact around the edges - just a general outline around and somewhat bigger than the area your are dodging or burning. PS settings can be different on which way the Curve graph is set up, so I can't tell you which direction to drag the graph line - just experiment with raising or lowering the line within the graph. 4. "Feather" the image using the keystroke sequence: Alt-Ctl-D (It's on the Select/Feather Menu, too). The number of pixels of feathering depends on the size of your selection and the pixel dimensions of the overall photo. Try 50 to start. You will see all your sharp lasso angles get smoother. This softens the edges of the Adj Layer you are going to make, meaning that the AL boundaries go from white to gray to black instead of abruptly from white to black. 5. Make a "Curves" adjustment layer. On the tools palette on the very bottom middle, click the little half-moon, yin-yang symbol and Select "Curves". A graph window appears. Click on the diagonal graph line and drag the line up or down to darken or brighten your selected area of the photo. You can click on a second point somewhere on the graph and drag it, too. For example, making the typical "S" curve like you see in film graphs, you can increase the overall contrast. Experiment. You are working on the AL at this point. Although you see the effect on the photograph, you are not affecting the original Background Layer. Don't worry yet about the selected boundaries on your image going abruptly from light to dark as you change contrast on your selected area. Click OK when the dodge/burn effect for most of your selection looks right. If you get too many anchored dots on the curve, simply delete them by clicking on a dot and drag it to outside of the graph. (Sometimes, feathering the lasso selection is enough to give you already what you want without needing to do the next adjustment layer step, but I usually find that applying the Gradient tool to the adjustment layer removes all traces of an otherwise obvious burn/dodge.) 6. Select the Gradient Tool on the tools palette. It looks like a step-wedge tablet going from black to white. After you click it, make sure you should also see the "step-wedge" selected at the top of the PS screen. 7. Click somewhere outside your selected area and drag across the edge of your selection boundary (usually perpendicular to it) and a bit into the selected area, where you want to feather the dodge/burn effect. In your AL, this will "paint" a gradient from black to white, if the little black/white squares are set correctly down at the bottom of the tool palette. If effect is wrong, try reversing the black/white squares by clicking on the curved arrow next to them. In your "Layers" palette, note there are two layers now displayed. In the palette, the adjustment layer should be highlighted gray (or blue?) as the "active" layer, and your Background layer will be white, which indicates that it is NOT the active layer. If wrong, just click a layer in the layers palette to make it the active one. 8. Try changing the Percent box at the top of the PS screen while your Gradient tool is active. By lowering it, you create a gradient that goes from gray to white, instead of black to white, giving a more subtle edge effect. The whole idea is got get a "fuzzy" mask (using your curves adjustment layer) around your dodge/burn selection, the same as if you were moving your cupped hands under the enlarging lens. If the effect of your gradient is too much, it's easy in PS to back up a step with the Edit /Undo menu or in the "History" palette. You can also delete the whole AL in the Layer Palette and start over - the above steps do not make any changes to your original Background layer. If the whole gradient thing is not working right, then something is set wrong at the top of the PS screen with your Gradient tool selected. It's a bit too easy to get some odd settings up there and lose the simple tool effect we're looking for. My setting across the top of the screen from left to right in PS CS2 shows: The Gradient symbol as dropdown selection, the regular checkerboard transparency pattern as dropdown, five types of gradients as little buttons (does not seem to matter which has the square around it), Mode: Multiply, Opacity: 100% (or some lower number for a more gradual gradient), Reverse - unchecked, Dither - checked, Transparency - checked. Note again that all of this has not affected your original "Background" photograph layer at all, so you still have the original photo to go back to anytime and adjust it again or delete any adjustment layers and start all over. 9. When I'm done or want to work on the file later, I always save it as a PS format file. Click "Save As", give it a name (or leave the same name as your original file, which was probably a .jpg or .tif extension) in the Save window and click the dropdown to pick the file type selection at the top of the list - Photoshop ".PSD". That keeps the file with both the original Background and with the layers you have added. (If you want to save the file at some future time as a .JPG file, you have to "flatten" the file - on the layers palette, click the top right arrow and click Flatten Layers. Don't do that though at this time.) If you can follow this lesson by-the-numbers above, it will become second nature with practice. Get the adjustment Curves layer dodge/burn approach working for you using the basic concepts of Select, Feather and Gradient. Then you can use the same technique for making other adjustment layer effects. Will be curious to hear if anyone actually tries this and if it made any sense! Best regards, Gary Todoroff (Tree LUGger) -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.385 / Virus Database: 268.2.6/287 - Release Date: 3/21/2006