Most everyone knows by now that the Sigma DP Merrill cameras have outstanding image quality at low ISO. The results in color are impressive, and the results in black and white are even more impressive. Yet as much as the Sigma cameras deliver at low ISO, they fail terribly at high ISO. Color results in particular are a blotchy mess. Here is an example of what you can expect from an ISO 3200 color conversion in Sigma Photo Pro (SPP): Completely unusable. Open the same RAW file in SPP "Monochrome" mode, and depending on the color balance, things don't necessarily look a whole lot better: Yet if you change the color balance to make exclusive use of the blue layer of the sensor, the results are substantially cleaner: The resulting conversion: It's still not as clean as a similar ISO 3200 photo taken with the Fuji X-E1 moments later: Still, by making use of the blue layer only in SPP monochrome, at least you can get usable high ISO results out of a DP Merrill camera. Here is another ISO 3200 color failure from my DP2M: And the blue layer conversion in monochrome mode: Conclusion: Depending on your requirements, the Sigma DP2M delivers usable results in B&W at high ISO, though it still can't match the results of current Bayer sensor cameras like the Fuji X-E1 in this regard. Low ISO black and white is another story. The Sigma DP2M simply excels there, but that is a topic for another post.