Tuesday, June 26, 2007
Extending Depth Of Field
Using multiple exposures and sound camera and software technique, you can defy the laws of physics
Use this technique to help register two exposures
1 Ensure you expose optimally. When bracketing for compositing, whenever possible, use a tripod, switch to manual focus and exposure, and lock down zoom lenses.
2 Layer two (or more) exposures. Open them in Adobe Photoshop. Go to the Layers palette, drag the Background Layer from one document into the window of the other, holding the Shift key before dropping the new layer down.
3 Check to see that the two exposures are perfectly registered by changing the Blend Mode of the top layer to Difference. The image will become very dark; if exposures are identical, the image will turn black. If the image isn't perfectly registered, you'll see brightly colored halos around contours.
In this case, use the Move tool or arrow keys to reposition the top layer so that the halos are eliminated. Finally, change the Blend mode of the top layer back to Normal.
A member of the Photoshop Hall of Fame, internationally renowned fine-art photographer John Paul Caponigro is the author of Adobe Photoshop Master Class. He teaches an array of workshops in his private studio. Get more than 50 free PDFs and test files, including techniques related to this article, at www.johnpaulcaponigro.com.
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