HDR is short for High Dynamic Range. It is a post-processing method of taking either one image or a series of images, combining them, and adjusting the contrast ratios to do things that are virtually impossible with a single aperture and shutter speed. I would say that about 75% of my images use the technique, and if you are new to it, then you may notice a slightly different "look and feel" to my photographs. You should also probably note that HDR is a very broad categorization, and I really hate categorization. My process starts with using basic HDR techniques, but then there are many more steps to help the photos look more... let’s say... evocative.
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