I tried to keep the four images as similar as possible: I set the tripod up in one position, and changed camera backs and lenses, but not the lighting or anything else. All four images were shot at f/8, with focus and shutter speed set by the camera. The only processing from the RAW files was white balance adjustment, and I made sure it was the same on all four. Once in Photoshop, I only did a crop to get 640x480 pixels, and I tried to crop as much the same section of the capture as possible. However, allowing for lens fields of view and sensor size, there's some variation.
Or maybe this is just reverse bragging that I got a D300 (back in August, actually).