What is HDR? Back to basics: the human eye can see a much wider range of light intensity than most cameras. HDR is a way to expand the range of light intensities that the camera's sensor records. Here's how it works: first you must capture a set of images that are identical except for shutter speed. Next, with your computer, you process the images to create a single HDR image.
The Easy Way: With the camera mounted securely on a tripod, compose your shot. Set the exposure as you normally would and take the shot. Lower the shutter speed by 2 stops without changing anything else and take another shot. Now increase the shutter speed by two stops from the original shot, and take the third shot. Use specialized software such as PhotoMatix, Photoshop, FDRTools, Niksoft HDR Efex Pro, or Canon's Digital Photo Professional to combine the images into a single HDR image. In Photoshop CC with Adobe Bridge, for example, select the images to be merged in Bridge, then select Tools > Photoshop > Merge to HDR Pro...
The Harder Way: This is similar to the Easy Way except that you determine more precisely how much to vary your shutter speed. You take light meter readings of the areas from least well lit to brightest, and devise a set of exposures to cover the entire range. Once captured, process the images as previously mentioned.
Many DSLRs have a built-in function called Auto Exposure Bracketing (AEB). While not designed for HDR, it is very useful. You can typically set up your shots for -2, 0 and +2 stops. It is convenient to use a 2-second timer delay to further reduce camera vibrations. Push the shutter release and the camera will automatically capture the three images in succession. More advanced cameras can even capture a set of 5, 7 or 9 images in this way.
HDR has become more mainstream in the past few years.Some newer high-end DSLRs now have a built-in HDR function. HDR is here to stay. I recommend that you become familiar with its uses.
Copyright © 2013 Philip N. Wheeler. All Rights Reserved.
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