Many times you see a beautiful scene and of course you snap a picture! The result is often far from being the magical scene you carry in your head. Our eyes are very adaptive and they are also more sensitive to intensity than color. It is estimated that our eye can see over a dynamic range of nearly 24 f-stops while a digital camera can capture a dynamic range around 6 to 9 f-stops. The High Dynamic Range Imaging is a set of techniques that has been developed nearly 20 years ago to overcome the limitations of electronic devices by combining multiple exposures into one great looking image.
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good for tone-mapping - I use it as a good complement to CS4 and DxO Optics