I'm travelling in Northern Queensland at the moment, sheltering from the colder winter of Brisbane and taking a few photos. I'm using a 5D as my primary camera and the 40D as back-up. The 40D is also attached most of the time to my 100-400 zoom. At F8 it should provide sharper and more detailed results than my 5D when a 600mm lens is required with full frame.
If the 40D were full frame, it would be a 26mp camera with a slightly greater pixel count than the 1Ds3 and pretty close to the much anticipated Sony A900.
Since I have my eye on the 24mp Sony as a possible future purchase, I thought I would do a bit of testing and comparisons between the 5D and 40D whilst out shooting today.
I used the 100-400 at 400mm, the TS-E 90/2.8, the 50/1.4 and the Sigma 15-30, all at F16, and other apertures, and all at the same focal length and from the same position.
It's not looking good. My suspicions so far are confirmed. You can't get more resolution than the 5D at F16, no matter how many pixels, unless you increase sensor size, or remove the AA filter (perhaps).
The following scene was chosen for its low contrast. I upressed the 5D shot, cropped to the 40D FoV, to the same file size as the 40D. I applied no further sharpening after upressing. Both images were converted with mostly identical settings, default sharpening, 50 clarity, 30 vibrance, but I forgot to equalise WB.
I'm searching for any low contrast detail in the 40D image that is not present in the upressed 5D image. I can't find any, but it will take some time to work through all the comparison shots I took.
Here's the first comparison, at 400mm and F16.
I'm working on an uncalibrated laptop, so apologies if the color sucks or the brightness/contrast is off.