Most digital files show noise at high ISO but also at low ISO in the the deap shadows. Noise removal can be tricky and also very time consuming if you use advanced tools like Neat Image or Grain Surgery.

Fred got some good reputation to make noise removal easy. His latest plug-in IsoX Pro helps you to get rid of some noise. We say "some" noise as you should not try to get rid of all the noise. Why? Because noise removal and keeping the details are at odds. The more aggressive you remove the noise the more you will lose detail. Fred's plug-in does a nice job in keeping as much detail as possible.

Here is an example of the Canon 1Ds file at low ISO 160.

Our intention is to open up the shdows a bit:

Opened up shadows

But here is what happens:

Shadow Noise at 300%

To reduce some of this shadow noise we run Fred's IsoX Pro plug-in:

We used it at level 4 and opted for the "Opacity Tweak". This will place a new layer on top of your current layers and allows you to tweak the strength by selecting a lower opacity of that layer.

IsoX Pro creates a new layer

Lower noise at 300%

As said we lowered the noise and did not try to remove it all. Finally you need to sharpen the image with your sharpening method of choice.

Note 1: Don't use IsoX Pro with 16 bits as it does not produce a useful result.

Note 2: We used IsoX Pro in a beta of Photoshop CS without any problems