Adobe Photoshop CS5 for Photographers - Martin Evening [95]
Figure 3.39 The curve shapes shown here approximate the curve shape that is applied by Camera Raw when you adjust the Contrast slider in the Basic panel.
One of the things that tends to confuse some people is the fact that there is a Contrast adjustment in the Basic panel as well as a separate Tone Curve panel for adjusting the contrast, and that these appear to perform the same function. But think of it this way: it is already quite common for people to apply a Contrast adjustment when they initially edit an image and then add a second Contrast adjustment later to fine-tune the first adjustment. There are basically three ways you can edit the contrast in Camera Raw and all of them are equally valid. You might decide the Basic panel Contrast slider is all that you need: just make a simple slider move and you are done. Or, you might choose not to use the Contrast slider at all and use just the Tone Curve to adjust the contrast. Alternatively, you might use the Contrast slider when applying an initial set of Basic panel adjustments, to get the contrast looking close to what looks right, and then use the Tone Curve panel to tweak the contrast further because you like the fine-tune control you get with the Tone Curve sliders. The important thing to understand here is that when you work with Camera Raw, it does not matter that you are applying a Tone Curve Contrast adjustment on top of a Basic panel Contrast slider adjustment. When the image is finally output as a JPEG, TIFF or PSD, all the adjustments you add to the image are eventually applied as a single adjustment.
Clarity
The Clarity slider is the first of three ‘Presence’ controls in Camera Raw. Adding Clarity to a photo can be thought of as adding sharpness, but it is more accurate to say that Clarity is ‘adding localized, midtone contrast’. In other words, the Clarity slider can be used to build up the contrast in the midtone areas by effectively applying a soft, wide radius Unsharp Mask type filter. Consequently, when you add a positive Clarity adjustment, you will notice increased tonal separation in the midtone areas. By applying a small positive Clarity adjustment you can therefore increase the local contrast across narrow areas of detail, and a bigger positive Clarity adjustment increases the localized contrast over broader regions of the photo.
How much Clarity should you add?
All photos can benefit from adding a small amount of Clarity. I would say, a +10 value works well for most pictures. However, you can safely add a maximum Clarity adjustment if you think a picture needs it (such as in the Figure 3.40 example shown below).
Figure 3.40 This screen shot shows an example of Clarity in action. The left half of the Camera Raw preview shows how the photo looked before Clarity was added and the right half of the preview shows Clarity being applied using a maximum +100 value.
Negative Clarity
Just as you can use a positive Clarity adjustment to boost the midtone contrast, you can also apply a negative Clarity adjustment to soften the midtones. There are two uses that come to mind here. Clicio Barroso and Ettore Causa (who helped beta test the Lightroom program) suggested that a negative Clarity adjustment could be useful for softening the skin tones in portrait and beauty shots (as shown in Figure 3.41 ). This works great if you use the adjustment brush tool (discussed on pages 227–235) to apply a negative Clarity in combination with a sharpening adjustment. The other idea I had was to use negative Clarity to simulate a diffusion printing technique that used to be popular with a lot of traditional darkroom printers.