Photoshop guru and acclaimed nature photographer Lewis Kemper writes, lectures, and teaches Photoshop across North America. Here he shares a Photoshop technique on how to fix an image that was exposed properly for the shadows but which overexposed the highlights.
LK: In this example we will pick an image with properly exposed shadows and overexposed highlights. I shot this image of Mt. Ansel Adams in the backcountry of Yosemite National Park on a 2 1/4 view camera. Unfortunately I forgot to use my Graduated ND filter. I did a good job exposing for the shadows, but in doing so, I totally blew out my highlights.
1. Open the image you want to adjust.
2. Next hold the CMD/CNTRL + OPT/ALT + 2. This will select the composite RGB channel in the Channels Palette. (marked here with red X)
This makes a selection based on the Grayscale values of the images. In plain terms, it selects the highlights of your image.
3. Create an empty adjustment layer, as shown in example below. Notice how the layer has a mask of the scene applied automatically based on our highlight selection.
4. Set the Blend Mode of the adjustment layer to Multiply.
Blend Mode set to Multiply.
5. To make the image sharper run a 3 pixel Gaussian Blur on the mask. (Filter>Blur>Gaussian Blur) This works in the same way Unsharp Mask, in the Sharpen Filters, actually sharpens an image. The science behind it does not matter, just accept that it works! You are blurring the mask so the original sharp pixels can show through.
Applying a Gaussian Blur.
This gives me a one stop Graduated Neutral Density Filter. The mask is not pure black and white, so there will be some darkening taking effect on the gray areas of the mask. If parts of the image get too dark, select a soft brush with low opacity and paint with black on the mask. If you paint on the mask I would run the sharpening blur after the painting.
If I want two stops I would:
1. Create an empty adjustment layer.
2. Group the Blend Mode to Multiply.
3. Copy this layer (by dragging the layer down to the New layer icon).
4. Create a Group. (Select the third icon from the left on the Layers Palette)
5. Drag both adjustment layers into the Group.
6. Turn off the Group by clicking on the eye to the left of Group.
7. Hold the CMD/CNTRL + OPT/ALT + the Tilde (left of number 1). While holding those keys Click on the composite RGB channel in the Channels Palette.
8. Turn on the Group by clicking on the eye to the left of Group
9. Create a Layer Mask on the Group. Notice the Layer Mask is filled with the image made from the selection.
10. Paint with black on areas that got too dark (in this case the foreground)
11. To make the image sharper run a 3 pixel Gaussian Blur on the mask (Filter> Blur> Gaussian Blur)
The Completed Image
And here are the before and the after with a two stop change.
Lewis Kemper sells his Photosop training DVDs “The Photographer’s Toolbox for Photoshop” on his website at https://www.lewiskemper.com/content/training_dvds.php
Use the coupon code DVD2011 and save some money!
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