The human eye can process the dynamic range (variation between highlight and shadows) of a scene 30 - 40 times more efficiently than even the best modern camera.
High-Dynamic Range Image (HDR) often explained as "seeing more like the human eye," HDR imaging combines several shots of a given scene to overcome the exposure range limitations of traditional single-shot photography - and the final results have much more detail from shadows to highlights, and everywhere in between.
As digital sensors attain progressively higher resolutions, and thereby successively smaller pixel sizes, the one quality of an image which does not benefit is its dynamic range. This is particularly apparent in compact cameras with resolutions near 8 megapixels, as these are more susceptible than ever to blown highlights or noisy shadow detail. Further, some scenes simply contain a greater brightness range than can be captured by current digital cameras-- of any type.
The "bright side" is that nearly any camera can actually capture a vast dynamic range-- just not in a single photo. By varying the shutter speed alone, most digital cameras can change how much light they let in by a factor of 50,000 or more. High dynamic range imaging attempts to utilize this characteristic by creating images composed of multiple exposures, which can far surpass the dynamic range of a single exposure.
We would suggest only using HDR images when the scene's brightness distribution can no longer be easily blended using a graduated neutral density (GND) filter. This is because GND filters extend dynamic range while still maintaining local contrast. Scenes which are ideally suited for GND filters are those with simple lighting geometries, such as the linear blend from dark to light encountered commonly in landscape photography (corresponding to the relatively dark land transitioning into bright sky). In contrast, in scene whose brightness distribution is no longer easily blended using a GDN filter is a perfect candidate for an HDR Image.
Some may argue that post processing an image using the HDR method is taking it too far. Many of us might have seen instances where we feel that the editing simply took over the image and it no longer represented the image that was produced from the camera. However, if used correctly, we believe that HDR could greatly enhance specifically landscape images (as illustrated by the image above).
We would love to hear your thoughts regarding this topic!
Nice post. I love HDR and shoot using this technique whenever given the chance. I just love the rich colors and dynamic range achieved. You make a great point about graduated filters as I feel the new age photographer forgets about things such as filters, gels, etc. Generally speaking, it's almost always best to get the image closest to it's finished product before it enters into the camera than to fumble around with software trying to "fix" what wasn't captured to begin with. HDR, however, is capturing what was there, it just needs help putting the pieces of the puzzle together.
ReplyDeleteIt's not the HDR that's overdone it's the tone-mapping! Hue and Saturation and general tone-mapping can easily be overdone in a normal photo just as well as an HDR. It's not the HDR process that makes the photo appear unrealistic. It's what we do with that file that ultimately determines the output.