There are lots of single image HDR presets and actions out there. None of them can replicate the look for a reason: they’re all LDR (Low Dynamic Range) images.
By definition, it takes multiple LDR images to make a single HDR. The main thing here is DR (Dynamic Range). Even today’s most powerful camera sensors are not capable of detecting what the human eye already sees: a wide range of tonal variations. The lightest part of a scene, the darkest parts, and everything in between.
All digital cameras meter a scene and determine an average. For the best example of this, take a photo of something that is very well lit on one side of the frame, and very dark on the other. It will never look right, no matter how much you fiddle with your camera’s settings. Parts of the image will always look overexposed while others look underexposed.
Exposure: 1/1250. Here you can see that this image is very underexposed. Most of the detail is lost in the shadows.
Exposure: 1/640. Better…but still underexposed in over 1/2 the frame, even though we have better lighting on the other half.
Exposure: 1/320. This is the middle bracketed image (#3 of 5) in this series and would normally be the “keeper” shot had this been just a single photo.
Exposure 1/160. Here we are entering the other end of the spectrum and most of the frame is now overexposed, even though we are seeing some detail in the shadowy area for the first time.
Exposure 1/80. Very overexposed. Even parts of the frame that were once black are now too bright.
The HDR result is below. I think you would agree that this can not be simulated with a single exposure.
By Anthony Hereld
Photomatix and Dynamic-Photo HDR are what I use, Photomatix is good, but Dynamic-photo can just bring out a different look and does a great job of faking HDR from a single pic. If you are getting into HDR then I would recommend that you have a look at Photomatix, there is a trialversion that is fully functional but watermarks your final image and see what you think. Happy HDRing