HDR, or High Dynamic Range, photography is a technique for combining multiple exposures of the same scene into a single photo that has a higher dynamic color range than your camera would be capable of producing on its own.To capture the HDR bracket photos, you can either do it manually, or some cameras support a function called AEB, or Automatic Exposure Bracketing. AEB isn’t really made for HDR photos, so most of the time you’ll be better off bracketing manually.
Merging the layers and doing the tonal mapping can be accomplished in any of the major photo editing programs commonly in use today like GIMP and Photoshop.
Another option is to go the easy way and buy a program specifically tailored for the job. If you’re going to be doing a lot of HDR work, it’s well worth the money.
One option is a program called Photomatix by HDRSoft. It comes in two flavors: Photomatix Essentials for $39, aimed at users new to HDR and Photomatix Pro for $99 which has a function called Exposure Fusion which makes natural looking HDR photos a breeze and is available for Mac and Windows users.
Mac users have the option of trying HDRtist. It’s a fairly simple program in terms of operation. Just drag your bracketed photos into the program and use the slider to adjust the exposure overlap. The basic version is free and pro version is $29.95.
Another option is HDR EFEX Pro by Nik Software, but at $159.00 it doesn’t seem to offer enough advantages to justify the price difference with Photomatix Pro.