Quote Originally Posted by Jon Ruyle
The test is fair only if both cameras get the same amount of light. No flash and equal lighting as you suggest would be good, but the shutter speeds *must* be the same.

Wouldn't you have to disregard the DOF difference of the two lenses. Pardon my ignorance here I am making this assumption, but to get the proper identical exposure even the aperture would be have to be the same in your scenario. Your subject would look different because of the 1.6x deeper depth of field so while the comparison would have the same framing the general feel of the picture would be different.