Every once in a while we run across another way to describe HDR photography. There is the ongoing controversy over whether HDR constitutes real photography. We think HDR is advanced photography.
Here's a great explanation of HDR techniques we found in NDTV Gadgots.
No matter how many people look at a photograph shot using the 'High Dynamic Range' (HDR) technique, there will always be a handful who will challenge its authenticity as a photograph, and claim it to be either a painting or an elaborately photoshopped image. The struggle of convincing people that HDR qualifies as photography has been a long and arduous one, with both sides being supported by prominent figures in the field. The primary bone of contention arises from a lack of understanding of what the HDR technique is, and towards that end, here is a point-by-point break down of the process and its history.
First off, we must clearly understand what the HDR technique entails. When we take a single photograph of a scene, our camera captures a certain amount of color information, a certain amount of brightness information and a certain amount of contrast information. By virtue of the laws of physics, the digital sensor is only capable of capturing a limited amount of information, an amount that is far less than what the human eye can comprehend.
The range of information luminance (combination of color, contrast and brightness) that the camera sensor captures for ONE exposure is called the dynamic range of the sensor. For most modern DSLRs, this number varies between 7 and 11 stops of exposure whereas the eye can easily recognize up to 15 stops of information. However, when speaking of HDR images, we are most concerned with not the luminance information, but in capturing the widest possible gamut of contrast range. While modern day digital sensors have a contrast ratio of up to 2048:1, the human eye's contrast detection ranges from 1024:1 to 16384:1. This large contrast range is what enables us to see the tree leaves as green despite the sun shining from right behind them in a blue sky. Shoot the same scene with a camera and the green of the color will turn black and the sky would go absolutely white.
