In my previous article, I showed you how the Adjustment Brush allows you to localize adjustments and constrain them to specific parts of an image by painting. Adobe Camera Raw (also known as ACR) provides a second way to adjust specific parts of an image: It lets you adjust color, saturation, and luminosity according to predefined subjective regions. For example, you might isolate the blues and aquas of a sky to emphasize just those colors, or everything else. These adjustment capabilities are aimed primarily at color correction. But they can also be used creatively, as pictured below.

In this article, we’ll take a close look at the ins and outs of working with the HSL/Grayscale panel and the Targeted Adjustment tool. Together, these features allow you to emphasize color, tone, and contrast within an image, as well as make expressive black-and-white conversions that far exceed what you can get by simply zeroing-out saturation.

This article is based on Chapter 24, Adobe Camera Raw, of Photoshop CS5 One-on-One: Advanced for lynda. com

You may remember the hues of the spectrum from school by the mnemonic “Roy G. Biv”, which sands for red, orange, yellow, green, blue, indigo and violet. When you shine sunlight through a prism, those are the colors we see, and those fundamental hues are the basis of how we relate to colors. Camera Raw’s HSL (Hue, Saturation, and Luminosity) panel essentially allows you to control the appearance of an image by dividing its colors into adjustable bands that correspond to those spectral hues.

With the HSL panel, you can independently adjust the reds, oranges, yellows, greens, aquas, blues, purples, and magentas in your image. The panel’s controls let you change the hue, saturation, and luminosity of each band.

As with the Adjustment Brush, any HSL/Grayscale adjustments you make are applied after the image is developed according to the basic settings. In fact, once you make satisfactory adjustments to the HSL controls, it’s often helpful to revisit the Basic panel to further refine the settings. Adding contrast after you’ve refined the hue and saturation of the colors can give your image the crispness that color contrast alone will not.

The Controls

The controls in the HSL/Grayscale panel are similar to those in Photoshop’s Hue/Saturation and Black & White commands, but they are more limited in some ways. For example, Photoshop’s Hue/Saturation command allows you to essentially map a given hue to any other, but the HSL panel in ACR only allows you to shift hues within their own distinct bands. The rationale here is that you’re trying to correct the image, not apply an effect. Even though this process is referred to as color correction, maybe it’s best to think of it as color enhancement, since you’re making subjective adjustments according to your own tastes.

When it comes to black & white conversion, one subtle but useful difference between the adjustment bands in ACR’s Grayscale conversion controls and those in Photoshop’s Black & White adjustment is that the ACR adjustment allows you to additionally target oranges, aquas, and purples.

• Oranges are related to skin tones
• Aquas are related to sea and sky

Targeting Colors

If you know which hues you want to adjust, you can move any of the HSL/Grayscale sliders directly. For example, you might decide that the reds in a shot of a bouquet of flowers should be more saturated. In that case, you’d click on the Saturation tab and adjust the reds. You can change the value using the slider or the value box as needed.

In cases where it’s less clear which color sliders are most relevant, you can point at an area with the Targeted Adjustment Tool to automatically select the appropriate color bands and adjust them by dragging within the image. The tool appears in the ACR toolbar, in the upper left portion of the ACR dialog.

Tap the T key to activate the Targeted Adjustment tool, hold the mouse button down in the image and then drag to adjust hues. The tool will sample the point where you click to determine which color sliders to adjust. You can drag horizontally or vertically, but once you begin to drag, you’re locked in to either horizontal or vertical gestures until you release the mouse button and start a new stroke. As soon as the direction locks in, a double-ended arrow will indicate whether the adjustment is determined by either horizontal or vertical movements. Dragging to the right/up increases the slider values. Dragging to the left/Down decreases them.

In situations where the targeted hue straddles two bands, you’ll see that more than one slider moves as you drag. One slider may move more than the other, and there will be times where you really just want one color band to move. In that case, you can readjust the slider that you did not want to shift.

You can also return any slider to its default setting by double-clicking on it.

Context Sensitivity

The Targeted Adjustment tool is context sensitive. Switching between the tabs in the HSL/Grayscale panel changes which controls will be affected. A check mark appears in the menu to indicate which property is being adjusted.

For example, activating the Hue tab of the HSL/Grayscale panel will place the check mark next to Hue in the Targeted Adjustment control menu. You can also go the other way around by using the menu under the Targeted Adjustment tool icon to activate one of the HSL tabs.

Side-effects

The HSL controls are useful for creative effects, but they’re best when applied with moderate settings. As you make more aggressive adjustments, you’re likely to bring out unwelcome artifacts.

Aberrant edges: Extreme shifts in tones can emphasize breaks between differently-colored areas. Returning to the dinosaur park example from the previous tip, we took advantage of the orange/blue color contrast to make the Tyranosaur pop against the sky. After opening the shadows and enhancing the orange color of the dinosaur, you could target the sky color and reduce its luminance. Pushing that effect too far created the off-color halo you see.

Noise: Another important side-effect of some of the more dramatic tonal shifts you can produce is that noise can become elevated, particularly where you’re substantially lightening dark areas. You can use the noise reduction feature in the Detail panel to help remove some of the noise. If you’re converting to black & white, you can use the color and luminance noise controls very aggressively to mitigate patterns of noise that can occur because of ACR’s edge detection functions.

Using Snapshots and Converting to Grayscale

Unlike presets, snapshots are stored as part of the develop settings of an individual raw file. Saving a snapshot allows you to play with different versions and switch between them to compare results. You can store as many snapshots as you like, storing many variations within a single raw file.

You’re likely to find images that look good in both color and black & white, and that’s one case where it makes sense to use snapshots. You can store separate snapshots of the settings that produce the best color version and the bast black & white version of the image, which allows you to switch easily between the two renditions.

The snapshot list displays alphabetically, so if you want your snapshots to appear in a specific order, start its name with a 1- or 2-digit number.

Steps for conversion to grayscale:

1. Apply cropping
2. Apply basic adjustments
3. Save your adjustments as a snapshot
4. Click convert to grayscale
5. Adjust the grayscale image
6. Save your grayscale snapshot

Conclusion

Combining these techniques with the adjustment brush will allow you to optimize the color and tone of your images before (and in many cases instead of) opening them in Photoshop. When you do use these non-destructive techniques for pre-editing your images, you’ll have a lot less work to do in Photoshop. And, if you read the article on Smart Objects, you’ll know that you can embed the raw file inside your Photoshop file and have the best of both worlds. Chalk up one more for the advantages of working in RAW.