Upload & Sell: Off
I have been trying to understand what I am seeing from my 50 MP, and why it doesn't match my expectations with respect to drawing style in one or a few types of situations, and today I was able to shoot 50 Planar and 50 Makro-Planar side-by-side in the same place I was shooting the 50 MP last week, so that I could start to see if there are any significant differences, and if so, what the differences are. I will post a few sets of comparison shots in the next day or so, but for tonight, I will post just one shot which I thought started to capture some of what I miss in the 50 MP, while simultaneously showing some of its strengths.
This all heavily relates to material covered by Samuli, Philber, Wayne and Adam, around page 55 and on of this thread.
This is the shot I will compare now:
Since I feel that a lot of the feel of a shot gets lost in the final resize step, I am posting here two links to 1800x1200 shots instead. Both shots are at f/2.
The three differences most visible to me are 1) the slight softness of the Planar in some areas of the photo, sometimes slightly tinged by purple, 2) the greater sharpness of the 50 MP shot, and 3) my elusive quality, the slightly better 3D effect (although weak in this shot) from the 50 Planar, via its more rapid DoF falloff, especially visible around the center of the image, near the ivy leaves at the base of the tree, but also in the distance. One can also observe the crap corners of the 50 MP near the bottom left and right, where sharpness suddenly falls off very rapidly, in addition to the unexpected sharpness in the top right corner, but I don't care about this (although I have to wonder why Zeiss didn't make this lens just a tiny bit larger to avoid this).
My personal summary of what technical aspect of the 50 MP has me missing something is something which has been mentioned as a characteristic of the 100 MP, namely that it has an extended in-focus region compared to other designs, which eventually falls off somewhat rapidly, but in this case never really catches up with the 50 Planar. The in-focus region is just too large for me for some uses, even wide open. For other uses, it is great, of course.
The comparison is slightly flawed, in that I did not manage to focus in exactly the same place (no tripod today), but I have compared maybe a dozen similar sets today, maybe even more, and they all show this same difference to various extents.
Note that the 50 MP is un-processed, other than sizing and normal sharpening, whereas I had to lower the exposure of the Planar by 0.6 stops or so (this was common among all Planar shots at f/2), increase the contrast by one click (in Aperture), and increase saturation by one click. Before making these changes (which worked uniformly on all Planar f/2 shots I made today), the 50 MP shot is a lot more attractive, but after making them, the 50 Planar shot is often more pleasing, for some reason, and I can't "fix" that by tuning the 50 MP shot.
In the end, the difference between the two was never huge, and often inconsequential, almost always giving the upper hand to the 50 MP, but on a few shots, the Planar had the something I have been looking for, and the 50 MP not. Therefore I think I will buy a 50 Planar at some point, and use both. First I will practice more with the one I have borrowed, to see if I can match some of Martin's urban 3D goodness, keeping the 50 MP on hand to do the comparison. For these tests, I will probably allow the 50 Planar to be shot wide open since the comparison is not meant to be technically fair, but to show what I can get in the best case.