Tuesday, September 15, 2009
HDR To The Rescue
High dynamic range saves the day in high-contrast situations
The +/- bracketing technique that I used for my lighthouse image isn’t set in stone for all HDR images. Sometimes you need to take more individual exposures covering three stops over and three stops under the “correct” exposure, such as when you’re photographing in very high-contrast situations. At other times, when there isn’t a wide contrast range, only one-stop bracketing is needed. What you don’t want is too few exposures. In my exploration of HDR photography, I’ve taken up to nine exposures at 1⁄2-stop increments to capture all the detail in a scene.
Before tone mapping
Before levels adjustment
In addition, you must leave your aperture constant, which means shooting in the aperture-priority mode (like I do) or in manual mode.
2. We need to combine our exposures into what’s called a tone-mapped image—the final processed HDR image.
The top photo at right is my image before tone mapping—what you’ll see on your monitor when all the images are combined using your HDR software. It looks strange because all the tones can’t be displayed on a monitor (or in a print). That’s where tone mapping comes in.
When you tone-map a series of images, you have two major options: using Details Enhancer and Tone Compressor—both of which have names that describe what they do.
For now, my quick advice is to play—and I mean play—with the sliders to see the effect each has on an image. A quick tip: The more you boost the Strength, Color Saturation and Luminosity in the Details Enhancer, the more surreal your image will appear; reduce these settings for a more natural look.
3. I used a bit of Levels adjustment (reducing the exposure by moving the shadow slider to the right) to create the opening image. I did that because I felt that the HDR image looked a bit flat.
The image at right is before my Levels adjustment. Compare it to the final image on the opening page and the exposures that I combined to create the HDR image, and you can see how amazing this technique is!
I have one more tip: Have fun! HDR imaging can open your eyes to a new world of creative possibilities—believe it or not!
Rick Sammon has published 31 books, including Rick Sammon’s Digital Photography Secrets and Face to Face: Rick Sammon’s Complete Guide to Photographing People. Visit www.ricksammon.com for more information on Rick’s HDR workshops.
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