Extremadura Sunsets (HDR)

by erikrasmussen, on Flickr")The point of high dynamic range (HDR) imaging is to, via post-processing, more accurately capture the wide range of colors and tones that the human eye sees as it saccades around the scene. Current camera photon sensing technology is just not as good as the human eye at capturing a wide range of light levels. The typical procedure involves taking three or more photographs of the same subject, with minimal camera movement, at various exposure levels, e.g. one where the shadows are underexposed, one where the highlights are overexposed, and another middle range. Then, using a computer program, the images are aligned and the detail from the shadows in one exposure is combined with the details of the highlights of another exposure, thus giving you detail across a wide range of light levels. Shortly before going on my summer vacation to Extremadura, in southern Spain, I learned about a auto-exposure-bracketing feature of my camera that lets me click the shutter button three times rapidly (while doing my best to not move the camera) and have it give me three photographs with a low, middle, and high exposure setting. I have finally gotten around to doing the post-processing of these sets of images, and I present them to you below.

Not HDR

These first two images are not HDR. They are one single shot with some post-processing to bring out the shadow details. By comparing these images with the ones below them, you should be able to see the limitations of post-processing a single image compared to the HDR technique of combining multiple photographs.

by erikrasmussen, on Flickr")

by erikrasmussen, on Flickr")

HDR

The following images were made by digitally combining three separate shots using the HDR tools in Photoshop CS4.

by erikrasmussen, on Flickr")

by erikrasmussen, on Flickr")

by erikrasmussen, on Flickr")

by erikrasmussen, on Flickr") And the sun has finally set.