Sharpening the Way You Like It: Photoshop Lightroom 2 Adventureby Mikkel Aaland
This excerpt is from Photoshop Lightroom 2 Adventure. Completely up-to-date for Lightroom 2, this beautifully illustrated and eminently practical book offers a complete tour of Adobe's integrated digital photography workflow application. Augmented by photos and case studies from a demanding road test in Tasmania, award-winning photographer Mikkel Aaland explains how Lightroom allows you to import, select, develop and showcase large volumes of digital images.
Lightroom's Develop module has four sliders that control image sharpening, as shown in Figure 4-75. For many, the control offered by these sliders is welcome. For others, using the sliders to achieve optimal sharpening may seem daunting. For those of you who don't want to spend a lot of time sharpening your images, I want to reassure you Lightroom's default settings are pretty darn good, especially if you are working with RAW files. There are also some out-of-the box sharpening presets that may be all you need.
Fundamentally, image sharpening is really just an exaggeration of contrast along edges, places where light and dark pixels meet. Lightroom's Amount slider controls the intensity of the edge contrast; the Radius slider controls how wide the edge is; the Details slider determines exactly what is an edge, and the Masking slider gives you more control over where the effects of the first three sliders occur. Let me show you what I mean.
The Amount slider controls the amount of contrast along the edges of an image on a scale from 1 to 150. In Figure 4-76, I bumped the amount to 150 and kept the other default sharpening settings. In Figure 4-77, I set the slider to 0. You can see here the extremes. For RAW files, the default amount setting is 25, a relative number based on the characteristics of your digital camera (see sidebar on the next page). For other files, such as JPEGs and TIFFs, the Amount is set to 0, which means no extra sharpening is applied until you move the slider.
The Radius slider controls how wide the edge is in values from .5 to 3.0. The greater the radius value, the larger the edge and the more obvious the sharpening. If you go too far with the radius setting, you'll get an unpleasant halo effect. Again, the best way for me to illustrate this is by example. I boost the radius to 3 (maximum) and the amount to 150 (maximum) so you can clearly see what is going on in this before and after shot in Figure 4-78.
An even better way to show what this slider does is to hold the Alt/Option key and then click on the slider. Figure 4-79 shows a radius setting of 0.5 (minimum), and, as you can see, a faint outline appears and few pixels are affected. Figure 4-80 shows a radius setting of 3 (maximum), and now you can clearly see the pixels outlined that will be affected when I move the Amount slider.
For all types of image files, the default radius setting is 1.0, and this is a good starting point. With JPEG and TIFF and other non-RAW files, you have to move the Amount slider before you notice any sharpening.
This slider works in a similar fashion to the Radius slider, but instead of working on a wide range of pixel values, it works on very fine detail. A setting of 100 (maximum) defines everything as an edge and increases contrast between all pixels equally. Lower values decrease the range and therefore the effect. Again, looking at the extreme setting is helpful. Figure 4-82 shows a before and after view with a detail setting of 100.
Holding the Option (Alt) key while moving the Detail slider clearly outlines which areas are affected at this setting, as shown in Figure 4-83.
The Masking slider does just that: creates a mask that controls where sharpening is applied. This control is especially useful when you are working with portraits or other images that contain large areas of continuous tones that you want to remain smooth and unaffected by increases in contrast.
Again, let's see how it works by example. Here, in Figure 4-84, I set the Amount, Radius, and Detail sliders to their maximum. In other words, I've totally oversharpened the image.
Next, I'll move the Masking slider to its maximum. You can see in Figure 4-85 how the sharpening (or contrast enhancement) is not as apparent in the skin tones. Holding the Option/Alt key while clicking on the Masking slider reveals the actual mask as shown in Figure 4-86. The black areas are the areas that are masked, or blocked.
Just about every image will benefit from some sharpening. The default settings may be a good place to start, but if you are willing to take the time, you can certainly do better. Knowing that every image demands different settings, here is a general strategy to follow:
- Make your color and tonal adjustments first. (These are detailed in subsequent chapters.)
- Select the Detail pane. You can turn sharpening off and on by clicking the switch icon to the left (circled).
- Select the triangle at the top right of the Detail pane window, circled in Figure 4-87, right. This opens and closes a preview window with a part of your image magnified to 100%. If you don't open the preview window and if your image isn't enlarged at least 1:1 (100%), a warning icon appears (circled in Figure 4-87, left). Click on this icon and Lightroom automatically enlarges the image in the preview window. Now pick an area that contains both detail and continuous tone (like an eye, hair, or tree branch against blue sky).
- If you are working on a RAW file, the sharpening amount setting is always 25 by default. In Figure 4-88 you'll see I find it useful to start by sliding the slider to 0 and then examining the image to establish a baseline for my next adjustments. Keep in mind that the effect of a 0 sharpening setting varies from camera to camera. With some digital cameras, the effect is barely noticeable. With others, it appears extremely noticeable.
- Next, move the Amount slider to 150, which, usually, is way off, as you can see in Figure 4-89. Again, I go to the extreme to visually establish a range.
- Through trial and error and going to extremes I come up with reasonable radius and detail settings. I look for a balance between sharpness of the edges, with no noticeable noise added to the continuous tone areas. You can mitigate noise in the continuous tone areas with the Masking slider. Hold the Alt (Option) key when using the Radius, Detail, and Masking sliders. You'll get a better idea of what parts of the image are being affected, as shown in Figure 4-90 and Figure 4-91.
- The amount of sharpening depends on the final output. If you are sharpening for screen, sharpen until it looks right. If you are sharpening for print, you will probably want to oversharpen to compensate for paper/ink absorption. (Print-specific sharpening is a whole topic into itself. There are many variables to consider, including printer characteristics, print size, ink, paper, viewing distance, and so on.)
- Finally, don't worry about getting it perfect (whatever that may be). Lightroom uses a completely nondestructive process, and you can go back at any time and start over.
Using the 1:1 Preview Window
Click on the triangle under Lightroom 2's Details pane and a 1:1 preview box opens, as shown in Figure 4-92. Clicking on the image enlarges an area to 100 percent view, or 1:1, as shown in Figure 4-92, right. Place your cursor over the 1:1 preview window, and you can click and move the field of view. If you click on the icon in the upper-left corner of the preview box, the 1:1 preview tool, the 1:1 preview window, and your cursor become synced to the image in the large display area. Wherever you place your cursor in the large display window, that part of the image will be enlarged in the 1:1 preview box. Click in the display area, or on the 1:1 preview tool, and the views become uncoupled.
Hold the Option/Alt key and the words Sharpen, Noise Reduction, and Chromatic Aberration turn into reset buttons, as shown in Figure 4-93. Click on them to reset the sliders to their default settings.
Additional Sharpening Control
You'll find additional sharpening control in the Lightroom Print module, which I cover in Chapter 11, and in the Export dialog box, which I cover in Chapter 9.If you enjoyed this excerpt, buy a copy of Photoshop Lightroom 2 Adventure.