Ray: As I have already stated, your two sets of 40D and 50D images are contradictory and in the second set I see no difference between the two suggesting no gain from the 50D. (Not being a Canon user I don't care about the outcome. It is academic to me.)
I cannot really comment on your latest examples (especially given your rather conflicting test methods from earlier posts) except to say that it looks to be somewhat of a miracle lens. My own careful tests with numerous micro/macro lenses agree with online MTF plots and show obvious drops at F16. And take a look at Rorslett's tests to see that he agrees, where he often says to avoid F16. I agree with him. Oh and my Sigma 400mm F5.6 APO macro lens (which is sharp) also softens noticeably at F16. Something is not right in your latest example. BTW I use a solid tripod, Markins ball head, mirror lock up and cable release in my tests.
Your comments are very puzzling. What do you find contradictory or conflicting? I provide you with test images I've carefully made for my own purposes. I label each one correctly, at the top of each image (did you notice that?). I tell you which converter I used and I tell you whether or not I applied sharpening (default sharpening in the case of ACR and no sharpening in the case of DPP). What is there to get confused about? I haven't secretly mixed DPP conversions with ACR conversions. I have
deliberately mixed F5.6 shots with F11 shots, and F11 shots with F16 shots, in order to demonstrate that the increased resolution of the 50D is roughly (perhaps very roughly) equivalent to the resolution of the 40D stopped up one stop, to a less diffraction limited F stop. That's just to give you an idea of the practical significance of the resolution increase of the 50D, in my view.
To my eyes, the DPP comparison of both cameras at F5.6 (no sharpening other than what's built into the DPP software and not user controllable) shows the 50D crop as having more detail and significantly less aliasing.
The same crops, but at F11 with the 50D and F5.6 with the 40D, and converted with ACR at default sharpening, also show the 50D image as having more detail, but this time the 50D crop has no aliasing whereas the 40D image has similar aliasing to the DPP conversion, but the magenta streaking is more subdued because of the different converter. One might deduce from this particular result that there's little difference in the sharpness of the Canon 50/1.4 at F5.6 and F8, despite the bar graphs at Photozone.
The first comparison of the rural/suburban scene, 40D at F11 and 50D at F16, both converted with ACR at default sharpening, look equally detailed to me depite both having received equal sharpening.
I haven't provided full details of the latest crops of the 40D at F11 and the 40D F16 because I wanted to demonstrate that you would be hard pressed to distinguish between them. The difference is not
significant, perhaps even invisible. This is not due to my using a miracle lens but is possibly due to my using a magical sharpening routine.... called 'Focus Magic'.
As I mentioned before, unsharpened one can discern an additional softness in an F16 image, compared with the same scene at F11 (from the same camera & lens). This requires just a little additional sharpening to correct. Both of these images were converted in ACR 4.6 using ACR's default sharpening of 25 at 1 pixel radius and detail at 25. The images were then further sharpened using Focus Magic's default settings for each image. Focus Magic is a deconvolution program which automatically suggests a pixel blur width to use, after a brief analysis of the image. For the F11 shot, it suggested 100% at 1 pixel blur width. For the F16 shot, the recommendation was 100% at 2 pixels blur width. Focus Magic could recognise that the F16 image was slightly soft, just as I could.
You probably know that DoF extends a greater distance beyond the focus plane than it does in front of it. Below are crops of the same images showing the foreground. Are you now able to tell which is F11 and which is F16?
For the record, the histogram of both images is very similar, same ETTR. The exposure of the F11 shot at ISO 100 is 1/80th, and the exposure of the F16 shot is 1/40th at the same ISO.
Is everything now crystal clear?