This test wasn't flawed because of the lens issue...
Good! A 75mm FL instead of 80mm gives a slight advantage to the 20D, but I think it's quite fair to give an advantage to the underdog, don't you?
As I see you are a painstakingly thorough sort of guy, I'll repost the images without any sharpening, WB adjustment or tweaking of the histogram. It has now occurred to me that the exposure differences in the earlier examples could have been partly due to the discrepancy in FL equivalence. The 5D shot takes in a slightly greater expanse of lighter shades. The true ISO values might also vary to different degrees between the 2 cameras, although I get the impression they are roughly the same.
I've converted the following images in ACR, with zero shadows and contrast, no sharpening, no luminance smoothing, no post processing, no nothing except EC adjustment, cropping. conversion to srgb and maximum quality jpeg compression.
I've reselected the images, but to get the histograms looking the same, I'm comparing a 5D image with 1/5th sec exposure and minus 0.9 EC, with a 20D image with 1/4 sec exposure and minus 1 EC. (Is this called fudging the results?) I've included screen shots of the histograms.
[attachment=927:attachment] [attachment=928:attachment] [attachment=929:attachment] [attachment=930:attachment]
Nope, it doesn't work that way, and you seem to miss my point.
Let me try to give you a visual analogy. We all know the common wisdom from the printing industry that a good print requires about 2x the raster lpi. Which translates to about 300dpi resolution for a common print situation and which is now also used for inkjet printing.
Oscar, I'm not suggesting I would print the 10ftx15ft image at the screen resolution of 96 dpi. Of course I wouldn't. I'd interpolate the image to 240 ppi with GF, as I mentioned. The file size would then be huge. The point I'm
making, which you seem to have missed, is that the 5 1/2" wide 400% crop which I'm scrutinising on my monitor from the distance one might view an 8x10" print, is part of a 10ftx15ft image. In other words, if I wanted to see the whole image at this degree of detail and at this resolution of 96 dpi, my monitor would need to be 15ft high and 10ft wide.