There are quite a lot of software programs able to combine several photo images into one HDR (High Dynamix Range) picture. But they are visibly not born equal. Camera Dojo compared several of them:
The first one produces pictures that are quite unimpressive (and rather dark), the last one is rather balanced and tries its best to produce very credible photos of a near perfect homogeneity. The second, Photomatix, outputs images totally out of the ordinary: If you want it to look HDR, this is the right one; but don’t look for realism if you are not able to use finesse and your best judgement against pushing the limits.
On the opposite, using the HDR feature of Photoshop is relatively easy and totally free (if you already spent a huge amount on the excellent Adobe software program).
To be noticed: He did not test qtpfsgui, open source and quite famous here; Neither did he try Artizen HDR which, for the very acceptable amount of 45.95 Canadian dollars, offers a lot of flexibility and parameterization to master the exact output.