Hi Joel.

That is the argument for the "crop reach" benefit, but it essentially assumes ideal scale up between crop and FF sensors. If ideal conditions existed, two 18 MP sensors with the same framing and same lens would give the same resolution. But they do not.

What ideal scale up neglects is the quality of the pixel on target, different sensitivity to imperfections in the lens (crop uses lens center more), and I am sure other factors.

I think a few people were entertained by this, but AlanF did an analysis of different online crop vs FF resolution test results. What he came up with was that the true benefit of crop vs FF in terms of resolving power was ~1.16x-~1.19x (numbers are fun... ). Very similar to what Rick just observed in his side by side tests, granted they are testing using different methodologies. Actually, Rick's test very much interested me as he was not holding framing to be consistent, yet made similar conclusions.