I've been lurking this forum for quite a while now and I must say I LOVE all the HDRs. From what I've read I know it's best to take at least 3 different photos with diff. steps and then combine them with photomatix. I'm curious though how to change the exposures from one image in order to make a HDR. I downloaded the trial version of photomatix and have taken 3 pictures with different exposures so I kinda know what I'm doing but I have some older pictures that I'd like to mess around with. Any help would be appreciated! Thanks!