Caution with Canon Digital Photo Professional 3.5.1 update, released December 21, 2008. The update introduced a disturbing side effect: detail-blurring noise reduction is enabled inappropriately, at least on two of my systems, and there is no warning from the software. This is the Mac OS X version; reader Timothy S confirms the same problem and fix for Windows.
DPP 3.5.1 defaults to Apply Camera Settings for noise reduction, or at least it did on two of my systems (Macs). The problem is that even with all noise reduction in the camera turned off, noise reduction is enabled at level 2 for RAW files, even at ISO 50 and ISO 100! I strongly recommend setting the DPP preferences for no noise reduction as follows:
RECOMMENDED (not default) settings for DPP’s Preferences/ToolPalette tab
See below: with the default DPP preference of Apply camera settings, all in-camera settings for noise reduction turned off, and ISO 50/100/etc, DPP still turns on level 2 noise reduction, which visibly blurs the image. And notice how the Apply is missing. It should be in the “NR” box.
DPP bug: noise reduction forced on even when off, and even at ISO 50, 100!