Global Chroma Noise Reduction in Photoshop

The latest generation of DSLRs are now capable of producing high ISO images of remarkable quality. Anyone who used to shoot film is constantly amazed at being able to do photography at ISO 1600 and higher with hardly any noise.
But once we get above 1600 noise starts to rear its head, and even the current low noise king, the Nikon D3, suffers from noise at ISO 12,800 and 25,600. This noise is mostly chroma noise, which means that it's in the colour information more than in the luminance, and while luminance noise looks a lot like traditional film grain, chroma noise is simply nasty looking.
In this Photoshop technique tutorial by Andrew Masur we learn one of several techniques that are available for reducing chroma noise in high ISO files.
– Michael

With the increasing dominance of digital SLRs, photographers find themselves shooting in more varied situations than ever before. It would be ideal if we could shoot at low ISO all the time, however this is rarely the case. While t...