Avoiding blotchiness in high ISO B&W conversions

[asabet]

Small sensor cameras often produce coarse, blotchy color noise in high ISO images. When converting these color files to B&W, the result frequently takes on a mottled appearance. I've found two ways to get around it, but neither way is perfect. The first is by finding a particular mix of color channels (or using the B&W tool in Photoshop/ACR) to eliminate the difference between the blotchy areas, and the areas that surround them. This can be effective, but often the results remain somewhat mottled. The other way is to use a combination of color NR in C1 v4 and coarse detail NR in Noise Ninja. This is effective in removing color blotchiness prior to B&W conversion, but the C1 color NR takes a real toll on overall detail and color fidelity. Compared to ACR/Lightroom color NR, C1 color NR is somewhat of a sledgehammer as the following GX100 ISO 800 example shows:

How are others dealing with this issue? Have you found any RAW apps that effectively deal with this issue for high ISO conversions to B&W?

 

[DavidE]

I feel your pain, Amin.

I've also been searching for a viable noise-management solution. That's the main reason I tend to reach for the DP1 (rather than the GRD2) when I see something worth photographing.

Have you tried Neat Image?

 

[asabet]

Hi David, I've tried Neat Image, Noiseware, Dfine, and others... The luminance noise doesn't bother me much, and the standard color noise is easy to deal with, but the patchy color blotches can be tough to remedy.