High ISO photography is common practice today and this requires at some point special noise removal tools. The Colormancer Boundary Noise Reduction filter is one of those.
We personally stay mostly in low ISO ranges (above ISO 400 is rather rare). We use also new cameras by Canon and Nikon that do a good job at higher ISO values. But we also tend to open up the shadows more than in the past. This means we get all the noise glory from the shadows. In the past we used any available noise tool and restricted the effect just to the shadows because even the best noise tools out there destroy some fine detail.
Colormancer Boundary Noise Reduction allows us to control the restriction to the shadows inside the noise filter. Here is a kind of classic example.
This is a Nikon D2x image at ISO 100. All is fine except that there is some noise in the black opening that we do not like and maybe visible on larger prints. This noise would also be much more nasty if we use a Tonemapping filter that opens up the shadows. Also some HDR images can benefit from shadow noise removal (e.g. using our Grunging technique).
We use Boundary Noise Reduction with the following settings (actually always on a new layer):
There are quite a few sliders but the available presets will get you started fast (read all the details here). In our case the main sliders are these:
What does this mean? Noise reduction is reduced or completely eliminated for highlights (in this case above 36 if white is 255). The threshold setting controls where this protection begins (here 25). The feather setting controls the range where the plugin transitions between full noise reduction and no noise reduction (here 11). This means only the very darkest areas of the image are effected by the noise removal. This is exactly what we want. This cleans the image nicely up without doing any harm the other image elements:
We also used Boundary Noise Reduction for other images (e.g. the slightly noisy Panasonic G1 ISO 400 photos) and liked the results too.
You can find more info here and even save 20% if you use the special DOP discount code (see below).