Both the 50D (firmware version 1.0.2) and 40D (firmware version 1.0.8) files have been interpolated to 4230x2820 pixels to simulate prints of equal paper size, and sharpened (after the interpolation) using Photoshop's (version 8.0) USM set to 200,0.2,0. The test target used was created to give an idea of both shadow and highlight detail in addition to high contrast resolution including for both positive and negative background transitions.

Note 1: Both cameras were tested using RAW format and developed via DPP. Using DPP's Preferences, both luminance and chrominance sliders have been set to zero; this was done prior to developing any files using the latest DPP (version 3.5.0.0). Also, the Contrast, Color Tone, Color Saturation, and Sharpness are set to 0, 0, 0, and 3, respectively. For both cameras, the Picture Style was set to Standard.

Note 2: Not that it matters but FWIW the 50D's in-camera "Auto Lighting Optimizer" has been disabled.

Note 3: The lens used in this test was a Canon EF 50mm f/1.4 USM. For both cameras, the lens was focused manually in Live View Mode.

Note 4: For both cameras, in-camera sharpness was set to "3" and all noise reduction was disabled.

Note 5: The 50D is very slightly overexposed relative to the 40D; to compensate for this the 50D files (and "only" the 50D files) have been adjusted by -0.2 EC.

Note 6: FWIW the object to sensor plane distance in this resolution test was 13.3 feet.