| When it came time to adjust this photo of a gravity-defying biker, the contrast between highlight and shadow information made it difficult to improve exposure. After trying Levels
and Curves with little success, the Shadow/Highlight feature, first introduced in Photoshop CS, revealed shadow detail and enhanced highlights the best—and the fastest.
|
|
To improve the exposure of my image, I tried adjusting the
Levels first. Although Levels is a great tool to correct exposure
problems, it’s not very useful for contrast problems. In my case,
moving the shadow point to the right made the shadows look
better, but when I adjusted the highlight slider, the lighter areas
of the sky just looked pale, washed out, and too flat.
|
|
I then experimented with Curves. In this case, I could lighten
the image, but at the cost of the shadow information. I tried to be
extreme with the midtones, and though the overall exposure improved,
the shadow areas (like the biker’s pants) were completely
black and silhouetted. They blocked up to pure black, which
wouldn’t reproduce with any detail at all.
|
|
To salvage the image, I needed a correction tool that would
fix the shadows and the highlights at the same time, so I tried
Shadow/Highlight (Image > Adjustments > Shadow/Highlight). Unlike Levels and Curves, Shadow/Highlight
is not an adjustment layer, so I duplicated the background layer
first. In most cases, you can achieve the results you want by adjusting
the Amount, but I needed more control over saturation and contrast, so I checked Show More Options and experimented.
Amount: Increasing the amount for Shadows lightens dark
areas; Highlights darkens lighter areas. Shadow/Highlight uses
image intelligence to analyze and differentiate adjacent pixels,
which is how I darkened the sky without making the biker’s
white T-shirt muddy and opened up the shadows without
washing out the black jeans.
Tonal Width: This helps balance the correction and avoid
halos that add an undesired glow around dark subjects. I used
a value around 60 in Shadows and Highlights. Lower values
restrict adjustments to darker or lighter regions. Higher values
include more tonal regions and midtones in the correction.
Radius: Similar to the controls in the Unsharp Mask filter,
Radius controls the width area around each pixel that is used
to determine whether an image area is a shadow or highlight.
I set the Radius by looking at the image and eyeballing the
percentages. The biker (shadow) is approximately 30% of
the image, and the sky (highlight) is approximately 70%.
Color Correction: Basically, this is saturation. I reduced the
standard value from +20 to +10 to offset any unwanted color
shifts and saturation that changing the exposure introduced.
Midtone Contrast: Set this to refine the image’s middle values.
I reduced the midtone contrast to even out the exposure.
The final image is shown below.
I may have achieved similar results with Levels or Curves if I’d
had more time to make tone-based masks and paint selective
corrections. Since the intelligence of Shadow/Highlight to
differentiate adjacent tonal values was so well implemented,
I could concentrate on improving the image without laboring
over complex contrast masks or tweaking controls.
The Adobe default settings of 50 for Shadows and 0 for
Highlights are much too lopsided and aggressive for most
images. To create custom defaults, open an image, choose
Image > Adjustments > Shadow/Highlight, and set the
Amount for Shadows and Highlights to 20. Click Show More
Options and check Save as Defaults. Click OK and if need be,
undo any image change. The next time you select Shadow/
Highlight, these more delicate settings will be your starting
point, and your image won’t be hit with a sledgehammer.
|
 Don't miss the next Photoshop tip on Graphics.com. Get the free Graphics.com newsletter in your mailbox each week. Click here to subscribe.
|
Katrin Eismann is the author of Photoshop Restoration
and Retouching and Real World Digital Photography. For
more information, please visit www.photoshopdiva.com,
www.digitalretouch.org, and www.digitalphotobook.net.
|
|
