This slide is made up of 100 percent crops from the center of our test scene. There's noise even at its lowest ISO, though you're unlikely to see it unless you are in fact pixel peeping.
Canon keeps a good balance between noise and noise reduction. Though most shots from the camera can benefit from a little post-shoot sharpening, it isn't until ISO 1600 that subjects start to look really soft at smaller sizes, and ISO 3200 is mushy and should be avoided.
This picture, and those that follow, are available for download to view at 100 percent. These are large files, though, so they may take a few seconds to open.