The question of "should I upgrade from the 10D to the 40D" comes up frequently. To help answer the question I've put together a comparison of both cameras shooting a real world scene at ISO-100 and ISO-800 (actually I also shot ISO-200 and ISO-400 but don't present the results in this gallery). Both cameras used the same lens (50 mm, f/1.4 @ f/8) and the camera was mounted on a really heavy (about 33 pounds) tripod. The shutter speeds were set identically for both cameras (at ISO-100 both bodies were set to 1/250 of a second and of course the shutter speed was 4 times faster at ISO-800). Also, everything you see in this gallery, except for "The Big Picture", represent screen grabs of the picture files that were displayed at 100 percent magnification via Photoshop. Oh, one more thing, both cameras were set to One-Shot AF and the center AF point was used to acquire focus; once focus was achieved the lens was set to manual focus simply to disable AF and eliminate variables associated with focusing.

By looking carefully questions regarding resolution, noise, and both highlight and shadow detail are easily answered.

Note, to more easily see noise in the sky (which is darn difficult to see in a properly exposed picture during the day), and ONLY for this screen grab, I decreased the brightness in Photoshop by -15 and increased contrast by +15; note, this change in contrast does not apply to any of the other comparisons in this gallery.

The RAW images from both cameras were developed using Silkypix at default settings, normalized in size via Photoshop (to a horizontal size of 3840 pixels), and then sharpened (Photoshop USM Setting of 250,0.2,0); this is to simulate what happens when you print two files on the same size of photo paper and then ask the question, "which camera is better."

PLEASE NOTE, 10D FILE NAMES START WITH (CRW_....) AND THOSE OF THE 40D WITH (IMG_....).