Tuesday, February 23, 2010
HDR Is The Question
When (and when not) to use HDR techniques
RAW files are packed with data—data from which you can expand the dynamic range of a single image. Note that you can expand the dynamic range of a RAW file only a few stops. That’s compared to many stops when taking a series of pictures for processing in software like Photomatix.
We’re back in Monument Valley. The bottom image is a straight shot that was processed in Adobe Camera Raw to expand the dynamic range. The top image is a Photomatix HDR file. Both images look pretty much the same when it comes to dynamic range because the contrast range wasn’t tremendous. However, it was wide enough to warrant expanding the dynamic range because the foreground and part of the background was in the shadows, while the butte in the far background was in strong sunlight.
When you want detail in both the shadow and highlight areas of a scene, you’ll need to think HDR, expanding the dynamic range with skillful processing of a RAW file or from a Photomatix image.
A note on the color difference between the images: I find that Photomatix tends to oversaturate strong colors, like the orange buttes in the background. Oversaturation can cause a loss in detail. Notice that the RAW-processed image shows more detail in the butte than the Photomatix-processed image.
I created this image from several images that I took in Upper Antelope Canyon in Arizona. What a magical place to photograph! Getting an even exposure in this cool location isn’t easy, however, due to the wide contrast range in the scene.
When the contrast range of a scene is very wide, HDR rules. However, just because you can almost completely open up the shadow areas of a scene doesn’t necessarily mean that you want all that detail in an image.
For this image, I wanted to include some of the shadow areas in the scene because shadows can add drama to an image.
Check out the files in the following illustration from which I created this Photomatix image.
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