Quote Originally Posted by neuroanatomist
to compensate for the narrower apertures, I increased Speedlite power.

You mean you gave the 5DII more light? Or do you mean you let the meter decide?


To make a fair comparison, each camera should get the same amount of light. So the shutter speed should be the same in ambient light, or the speedlight should be set to some fixed *equal* output value rather than relying on the meter. The 5DII will probably require a higher ISO to expose reasonably.


I don't think you stacked things in favor of the 5DII by using different shutter speeds, but if you let the meter decide, you ultimately allowed the meter of each camera to decide how much light to give the sensor. This could lead to a largeish difference one way or the other (I have no idea which way the bias would be, though)


If you told the flash to give the 5DII more light to compensate for the smaller aperture, you stacked the test heavily in favor of the 5DII. (I don't think you did this, though, because the 5DII would appear brighter if you had... after all, you already mostly compensated for the narrower aperture with ISO)


Unless the DXO Mark guys screwed up, the 7D should come out ahead in this comparison. It has lower read noise and lower photon noise.