i guess you guys are familiar with bruce fraser's real world camera raw. he gives a good example in chapter 5 of recovering an underexposed image. i've read and re-read the example a few times, and if i understand correctly, all i can do is make sure there is no clipping and no posterization and finally increase luminance smoothing as much as needed. really all i do is what i usually do in terms of workflow, with the only noticeable difference in his example being that he adjusts white balance after making the tonal adjustments, not before. obviously the data that was lost because of the underexposure is simply lost, nothing can be done to retrieve it. i guess minor underexposure is ok, sometimes even desired, but severe underexposure like in my case is hard to correct. i have the same pictures taken with the right exposure and underexposed 2 stops, and it's actually a good exercise trying to see how close to the first i can come with the second. but this "noise" thing keeps coming back! this lesson has been learned!
p.s.: russell thanks for making me feel a little better. stupidity is always more bearable the greater the numbers! now i think my bamboo kon tiki is ready.....
amnon