I am 100% with you on this. I had prints in mind in the first place.
A2 is enough isn't it? No resampling done in PS, we just pick a 21 inch lenght (so as to be able to use an Epson 4000/4800 or HP 130) and compute the DPI needed without doing any up-sampling in PS. Then we let IP (for instance) do the job of printing the image the best it can.
The best would be to request the brands to send a representative able to use each piece of equipment at its max, gather everybody in one/two locale(s) and start shooting 4 or 5 scenes that everyone agrees on. For instance:
- one fully static scene in morning/evening light with a near/far composition featuring lost of small details both in the foregounrd and in the distance -> check DoF, overall sharpness, colors, WB and shadow noise,
- one scene with moving water (river or waves) -> this will put pressure on stitchers,
- one back lit scene including the sun in the image, branches,... -> check DR, highlight rendition and CA,
- one panorama shot,
- one macro shot.
I agree with you on stitching coming out as the sharpness winner, although you lose the DoF advantage of the smaller format all things being equal.
But there is more than sharpness. We should also take into account:
- The time needed to come up with the print,
- The DR achieved (overlaying being a valid technique),
For the test to be perfect, we would also need all these cameras to be mounted on the same tripod (say a Gitzo 1227/1257) with the same ball head (say a BH-55)... which makes things a bit comples. It should be possible to come close enough though.
Wondering if Michael would be interested in conducting this. If he is not, it could be fun to try to do it in Japan. I wonder if the back resellers would be interested in cooperating with such a test...