I've heard that it's possible to create an HDR image from a single RAW file. (Obviously, it won't be as good as using multiple bracketed RAW files; I know that much.)
Every time I try — using Photomatix with the default settings -- the results are truly awful. I'm not even trying for something printable, I mean it's too noisy, blotchy and generally horrible even for viewing onscreen.
Does anyone have any tips — either about what kind of RAW files will work well, or about how to tweak the Photomatix settings for this case, or about other software which will do this better?