HDR programs get a bit muddled by too many very dark or very bright exposures. Sparse sets of brackets seem to work better in most cases. One pragmatic approach is to set the sliders to something like a typical range, then experiment with various selections from the bracket set to see what works best. In your posted image, in the dark areas I think I see the result of the software trying too hard to bring up severely underexposed bracket set members in the dark areas near the floor.
It looks as though this situation warrants further experimentation. It's far better to get the right mix of exposures at the time of taking the shots, than spend hours messing around on the computer trying to fix things. One feature of the Nikon D700 that attracts me is its wide range of exposure bracketing. If I've understood the specs, this camera can bracket up to 9 consecutive shots with an interval up to 1 EV between shots. That represents a total range of 8 stops.
The image I posted of the hotel room in Nepal
does have noise in the shadows. I used just 3 images with a range of +/- 2 stops. However, on that occasion my 5D was on a tripod and I took 3 lots of bracketed exposures of the room. The problem, I suspect, is that only one of those exposures was correct for the highlights. If I'd had one or two more shots which were
underexposed with regard to the highlights, I think the HDR merge would be completely successful.
Here is a CS3 merge to HDR of 6 shots of the same scene ranging from 1 sec exposure to 1/60th, which represents a 6 stop bracketed range. It seems even a 6 stop range is not sufficient for HDR to work successfully with this scene. Out of the 6 shots, 5 are overexposed with regard to the highlights. I think I probably needed at least one additional image that is significantly
underexposed with regard to the highlights.
You can see from the lightened crop of the dark area that the shadows are now quite clean. However, the mountain peak is still the same, as in the previous comparison.
[attachment=10271:1722_23_..._HDR_CS3.jpg] [attachment=10272:crop_of_floor.jpg]