Everyone is disappointed, when they first start taking photos, with the results they get in tricky lighting situations. You’re in a lovely cottage with a spectacular view of the country out the window. You can see the details in the drapes and the fluffy clouds. When you look at the photo, after taking great care with the exposure, you see a washed-out sky in a black rectangle. The reason? Your eye is able to capture much more of the “dynamic range” of the scene – the shadows and highlights – than any camera sensor can.
HDR is a photographic technique that usually uses three or more exposures (images) to capture all of the dynamic range that your eye sees – sees without any effort on your part. These multiple images are then merged together so that you have properly-exposed highlights, midtones and shadows. I covered two camera apps that use this merger technique back in February 2013.
Other apps, rather than needing multiple exposures, will try to improve the overall exposure of a single image. Snapseed and iColorama have HDR components, and many other photo suites do as well. JixiPix has a stand-alone single-image HDR app called Simply HDR.
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