Quote Originally Posted by Jon Ruyle


Quote Originally Posted by neuroanatomist
Jon, Rick, how would you suggest I set that up? I'm thinking of shooting the ColorChecker, using the same lens for equal transmittance, but...the 100 L Macro and change distance, or the 70-200/2.8 II and zoom to compensate for crop?). Manual exposure, same aperture for both cameras (since sensor size doesn't affect exposure), and a flat target obviates DoF. What else?

I think you're making it too complicated. Set your cameras so they take the same picture (as you have done with different lenses and the same aperture). Give them both the same amount of light (ie, same lighting, same shutter speed). Then you have a fair comparison. I would suggest using manual mode under the same lighting and no flash, and setting the ISO so the pictures look similarly bright or so the histograms look similar (ISO does not affect photon noise).


Transmission will be different because the lenses are different, but I don't think that is a biggie, and I don't see a way around it (using the same lens on different cameras with different f/ settings will not give exactly the same transmission percentages eithe


John


Using the same lens and adjusting distance should work, If you are just checking noise. I think low even light would be the best since you are trying to make noise.


I think Jon's suggestion would work. But how are you going to quantify the noise. And would there be some ratio that one shows more noise than the other, for instance the 7D would have 1.6x the amount of noise of the 5D? Which I am sure will not be the case.


Rick