"Aspects of Noise Reduction in RAW Data"

Night photographers are often concerned about digital noise when shooting long exposures. New cameras are able to exposure beyond ten minutes without producing unacceptable amounts of noise. Some high-end DSLR's have been reported to be able to shoot over one hour. But noise is still there, and both in-camera and post-processing noise reduction techniques are always of interest in night photography.

And then there's thermal noise. While most modern DSLR's can control that magenta or blue amplifier glows, noise still increases in warm weather. It's always there. The question is, "How much can you tolerate or control?"

If you can't read enough about digital noise, check out Emil Martinec's great article "Aspects of Noise Reduction in RAW Data". This is some pretty technical stuff. But it makes great reading if you have the time to read through it slowly.