Professional Information Technology-Programming Book part 24 doc

Chapter 6. Nondestructive Overall Adjustments The workflow organization of this book is about maintaining nondestructive editing in as many ways as possible for as long as possible. So when it comes to making post-RAW or non-RAW overall adjustments, you want to start by doing them with adjustment layers. That's because an adjustment layer doesn't actually do anything at all to the image itself. The adjustment layer simply passes on a text description to Photoshop to display the image in certain ways. You can even go back to that layer and change those instructions at any time. But, you say, what about all the Image Adjustments commands that are not available as adjustment layers? Do not use them until I tell you to, that's all. When that time comes, I'll show you a keyboard shortcut/Action alternative that will place the effects of those commands on their own layer, so they don't affect your previous work. Of course, there's no written law that says that you can't do these things in any order you like. On the other hand, the whole point of this book is to discipline you to sequence your work so you'll never have to recreate any more of an image than is absolutely necessary to make the desired change you want to make. Adjusting on Adjustment Layers Once you've done your spot retouching and lightened or darkened (burned and dodged with the 50 percent gray layer), it's time to adjust your image. You'll probably want to make adjustments at this stage, whether you're working on top of adjustments you've already made in Camera Raw or starting from scratch, because your camera shot a JPEG or TIFF image. Also, if you made adjustments in Camera Raw, you'll be happy to know that there are even more overall adjustments that can be done only in Photoshop. This chapter only discusses the adjustments that can be done on adjustment layers because they are completely nondestructive. In Chapter 12, I'll show you how to make destructive adjustments on a separate layer. A.4. Adobe Lightroom On the other hand, if you're a Mac user, before you decide on Aperture, download and test Adobe's Lightroom Beta. If you go to http://digitalmedia.oreilly.com/lightroom, you'll find a whole new "Overview" chapter on the Beta 3 version of Lightroom and exactly what it can do. In fact, you'll find a whole web site dedicated to this new product that will keep you up-to- date with what is surely a future workflow linchpin. It isn't as pretty to look at as Aperture (although it is quite lovely all the same), or as feature rich (yet Lightroom is far from finished). On the other hand, Aperture costs more and takes significantly more computer overhead. All I'm doing here is telling you what's really worth your consideration. The thing about workflow products is that the complexity of workflow takes time and energy to set up and organize. So whatever you settle on is going to be very hard to let go of. NOTE If you're a Windows user (and now the majority of Photoshop users are), Aperture isn't a choice, but Lightroom is now available in a rough beta. The thing that really makes choosing Lightroom a no-brainer is that the routines for adjusting the image include everything we are already familiar with in Camera Raw. So there's very little to have to re-learn and a whole lot to gain in terms of speed and efficiency. 6.1. The Basic Levels and Curves Routine The best place to start, once you've taken your image past the RAW stage (or if you shot JPEG or TIFF), is with a pair of adjustment layersone for making Levels adjustments and one for making Curves adjustments. Of course, you are wondering why on Earth you'd want to do that since you probably just made adjustments in Camera Raw. Well, one of the advantages of working with adjustment layers is that you can use the same adjustment several times on the same image. It may be possible that your image is so perfect right out of the camera or out of Ca mera Raw (or RAW Shooter, Capture One, Aperture, or Lightroom; see the Appendix) that there's no point in going any further. After all, one of the characteristics of a great artist is knowing when to stop. On the other hand, you don't want any more barriers than what your medium forces you to accept. I feel that I owe it to myself to try the tweaksunless time simply doesn't allow it. NOTE As I mentioned in Chapter 5, one of the things I've done to save you time is create an Action (actually it was Doug Sahlin's idea) that I call the magic Workflow Layers Action. You can download it from either the O'Reilly site (www.oreilly.com/catalog/digphotoet/) or from www.kenmilburn.com. Figure 6-1 shows the Layers palette (choose Window Layers) as the Action configures it. Load it. It will save you hours of time every monthor at least until you rerecord it with even more layers tailored to your own workflow. The rest of this chapter assumes that you are using it. Figure 6-1. The Layers palette that the Workflow Layers Action produces. Assign this action to a key that doesn't conflict with anything you do often. After opening your image from Bridge, use both the Levels and Curves commands to tweak the adjustments that either your camera or Camera Raw made to the original image. Levels are used to fine-tune the values in the three main areas of the image, much as if you made a simple S-curve in Curves. Then you can use Curves to tweak the contrast in two or three additional brightness ranges within that same image. Don't bother yet with masking these channels. Chapter 7 describes numerous techniques to create masks for layers and then use them to adjust very specific areas within the image. This is another step in the workflow called Targeted Adjustments. NOTE Make sure you exported your files from Camera Raw (or whatever application you use to process your RAW files) as 16 bits. In the last three or four chapters of the book, you may have to switch to 8 bit. However, in the meantime, you want to maintain as much data in the image as possible to keep posterization to a minimum for as long as possible. 6.1.1. Levels for Shadow, Highlight, and Overall Brightness This is the Levels routine I use on all my images. When I finish, I know it is exactly as I want it. Then, if I want a certain effect, I can come back and modify this command as the interpretation I'm ultimately looking for begins to shape up. 1. Go to the Levels adjustment layer that was created by the Workflow Layers Action or any layer. Double-click its Layers icon. 2. Adjust each color channel individually. Don't make any adjustments in the RGB channel until the very end of this exercise. Press Cmd/Ctrl-1. The Red channel's Histogram appears. Look to see if the Histogram mountain "touches ground" at either end before it reaches the frame. If it does, move that end's slider (Highlight or Shadow) just barely to the left of the touchdown point. Do not touch the midpoint slider. NOTE Don't perform Steps 2 or 3 if you used a color or grayscale card to match color balance in Camera Raw (e.g., for predetermined colors for catalogs or logos or because you wanted white balance to be correct regardless of subjective considerations). 3. Repeat Step 2 two more times, once after pressing Cmd/Ctrl-2 for the Green channel and once after pressing Cmd/Ctrl-3 for the Blue channel. The colors in the image are now balanced. You'll probably be surprised at how much better it looks. 4. Adjust Brightness, Contrast, and Midtones by using the composite (aka RGB) channel's Histogram and sliders. Adjust the Highlight and Shadow sliders just as you did in the color channels. This is often not necessary because of the adjustments you just made, but if it is, follow Nike's advice and just do it. 5. Adjust the midtone slider to get the overall brightness you want. Don't even try to get the right look for a specific area of the image just because it's important. Not nowit's just not the right time. You want the overall balance to be right. Figure 6-2 shows the before and after of an image. Figure 6-2. Before (left) and after (right) levels adjustment. 6.1.2. Curves for Adjusting Contrast in Specific Brightness Areas Now is the time to get the brightness and contrast correct for the most intere sting or decorative portions of the image. Which area this is will depend entirely on the picture you've taken and your interpretation of it. You may want to darken some blocked highlights, or increase the contrast in the midtones to make the subject of interest "pop" or to simply block some shadow detail in a specific area so that it doesn't cause a distraction. This will probably be easier to visualize if we start with an example. Figure 6-3 shows an image after it was treated with the Levels adjustment layer but before using the Curves routine described next. The right is the result of the Curves Layer adjustments. Figure 6-3. The image after adjustment with the Levels layer (left) and adjustment with the Curves layer (right). Here's the step-by-step process for changing the Curves adjustment layer for several specific areas of brightness in a given image: 1. Double-click the Curves icon in the Curves adjustment layer bar in the Layers palette. The Curves adjustment dialog appears (see Figure 6-4). Figure 6-4. The Curves adjustment dialog as it appears when first opened. 2. Place your cursor over the area you want to change and press Cmd/Ctrl. (I find that it's generally the mid-highlights and shadows that need a bit of added contrast, as well as some lighteni ng or darkening.) The cursor changes to a dropper. Click while the dropper is exactly over the color you want to change. A spot will appear on the Curve line at the exact point that corresponds to the brightness level you picked. Leave it alone until you've picked another couple of areas that need changing. 3. Look at what you have. You will want to raise the points that represent the areas to brighten and lower the ones to darken. Check the Preview Box so you can see what you're doing. I find it is easier to change the position of points with the arrow keys because the changes happen in small and exact increments. As you raise or lower the points, notice that the contrast of areas between the two points increases as the Curve line becomes steeper. You may want to plot additional points to change the shape of the curve. To isolate a point so that little changes on either side of its brightness, place two points on either side. This will keep the curve from moving. Figure 6-5 shows the Curves adjustment layer dialog as it looked after the adjustments from the right side of Figure 6-3. Figure 6-5. The Curves dialog after making the necessary adjustments to get the results shown in Figure 6-3. NOTE With a little practice, you may know in advance what you want your curve to look like. When that day comes, you can save a lot of time by choosing the Pencil tool in the Curves dialog and simply drawing the curve freehand. It is usually a bit jerky, but you can click the Smooth button. The curve is still modified by clicki ng points and dragging them. . Chapter 6. Nondestructive Overall Adjustments The workflow organization of this book is about maintaining nondestructive editing in as many ways as possible for as long as possible you can't do these things in any order you like. On the other hand, the whole point of this book is to discipline you to sequence your work so you'll never have to recreate any more. application you use to process your RAW files) as 16 bits. In the last three or four chapters of the book, you may have to switch to 8 bit. However, in the meantime, you want to maintain as much data