I've recently started dabbling with nighttime photography - 30-second exposures at high ISO, for now, since my camera can't do more than 30 seconds without a remote switch. (Don't worry, I've ordered one.) Anyway, at ISO 1600, I wind up with a lot of chromatic noise, especially if I do color correction. Bad!
Fortunately, a fellow photographer recommended Imagenomic's
Noiseware. It's available in standard and pro levels as a Photoshop plugin for Mac OS X, and as a plugin or a standalone application for Windows. I grabbed the Noiseware Standard plugin for Photoshop and was rather happy with the results. To my eye, the night sky still has patches that look faintly more magenta than other patches, but I'm being incredibly nit-picky to even point that out. Overall, the before-and-after difference in visible noise is, to use the worst possible cliché, "night and day." This image is just a tiny crop from
one of my night shots.