I'm interested in doing City scene HDRs at night. Some of these scenes have lots of range, and reflection which can benefit from HDR. However, the low light can cause problems because you have to crank the ISO and this results in noise. Plus, when you run images with noise through an HDR program like photomatix, it results in amplified noise and a completely useless photo. How do you guys create nighttime cityscape HDRs? If I kept my ISO at 100, I'd get nothing. Do you run it through noise software first. I don't have a particularly noisy camera (Canon 40D), but I still find these shots impossible. The most promising solution that I was investigating was the use of image stacking software to remove the noise, and then create the HDR. I downloaded the trial for PhotoAcute. With PhotoAcute, you can shoot your bracketed as normal, but instead of one set of bracketed shots, you would shoot like 10 shots. You can run each set of +2/0ev/-2 through PhotoAcute, and it will stack the images and remove the noise because of the principle that noise is random. It actually works amazingly well. However, when I take the resulting noise free TIF files and run them through photomatix, it doesn't work. After spending my entire Saturday trying to figure this out, I'm completely frustrated and need help. How do you guys do it?