To illustrate my proposal that the 50/1.4 is sharper than the 58/1.2, I am starting with center sharpness and corners will come later.
In the process of adjusting infinity focus on these 2 lenses, I took this series of shots after I was done. They were exported out of LR directly from raw. The 1.2s warmer color I think was due to a skylight filter, and not a UV. The crops were all done identically. You can see the 8mm difference in field. The wider open shots were a little overexposed because of the high light levels, but I was concentrating on those poles across the valley floor at the time.
1) Why use filters at all for this sort of test, especially different kinds of filters?
2) In all the shots, the foreground of the 58/1.2 is blurrier than the background, indicating that you are a likely a hair beyond infinity.
3) It is fairly well-known by now that the 58/1.2 hits peak resolution at f4. Your f4 results do not reflect what I have come to expect from my sample of the lens, so I suspect it is not an ideal sample or that 2) is in fact true.
1. As I said, I did this after adjusting infinity focus. If I set out to do a test I would have probably removed any filters.
2. No, sir. My lens adjustments are exact. I go through many iterations to get the best sharpness at wide open aperture. There is a leveling off point where the lens stays sharp with a slight tolerance. I always find that point, and therefore eliminate any misfocus issues in the comparision.
If there is blurryness in the foreground, it is inherent in the lens design. It is also easy to compare with the 50/1.4, with greater DOF due its own design and slightly wider 50mm focal length.
3. That's not fairly well known to me, not that its not reasonable to have good performance at f/4, but I see the f/5.6 photo showing slightly more detail. Wait until you see the corner sharpness differences, on a crop camera yet.
It's my opinion there is fairly good consistency of performance in these lenses. I feel these lenses are good representatives of the 50-58 Rokkors.
Additionally, my lens conversions do indeed eliminate any misalignment issues common to adapters.
This concept is not that hard to understand. The sharpness and contrast differences are real between these lenses.
I have a 58 1.2 and a few 50/58 1.4s (one from Jim) and had the impression that the 1.4s are a little sharper ... however, none of them match the 1.2 bokeh, which is the main attraction of the 1.2 in my opinion.
Not to beat a dead horse, but I have finally realized why the comparison shots, here, reflect different color tempertures.
I am confident of the sharpness, focal length differences of the lens FOVs, and accuracy of infinity focus assertions I have made.
The difference in color temperture between the 58/1.2 and 50/1.4 is not because I left a skylight filter on the 58/1.2, or any filter for that matter, as my method is to not use filters. The reason should have been suggested by an early Rokkor 58/1.2 owner as those lenses use radioactive glass that apparently yellows with time.
I had just finished a second version 58/1.2 EOS conversion and before I boxed it up for shipping, I took comparison photos for infinity focus sharpness between it and my own late serial# 58/1.2. I had no filters on either lens. Although the 2 lenses were equal in sharpness, the early second version 58 was noticably warm in color tone. I understand that the yellowing can be reversed with UV light, but the mystery is solved, at least in my mind.
JimBuchanan wrote:
To illustrate my proposal that the 50/1.4 is sharper than the 58/1.2, I am starting with center sharpness and corners will come later.
In the process of adjusting infinity focus on these 2 lenses, I took this series of shots after I was done. They were exported out of LR directly from raw. The 1.2s warmer color I think was due to a skylight filter, and not a UV. The crops were all done identically. You can see the 8mm difference in field. The wider open shots were a little overexposed because of the high light levels, but I was concentrating on those poles across the valley floor at the time.
Good thoughts re: yellowing. Indeed it can be cleared, I cleared one with a cheap UV LED flashlight. Took several sets of batteries over the period of a week or so but it completely cleared.
Ed Sawyer wrote:
Good thoughts re: yellowing. Indeed it can be cleared, I cleared one with a cheap UV LED flashlight. Took several sets of batteries over the period of a week or so but it completely cleared.
-Ed
Anyone use a UV lightbulb? Sunlight works too, of course. Nice thing about UV is it kills fungi too.
I hesitated putting this post back up, so as not to discuss sharpness, again. My point was the reason for the color shift between the 2 lenses. I couldn't believe I was comparing 2 lenses and forgot to remove a skylight filter. Well, turned out there were no filters on either lens, rather high refractive, radioactive glass in the 58.
Also, I never said the 58/1.2 wasn't sharp wide open. I demonstrated the MC 50/1.4 was sharper at every aperture from f/1.4 on and across the field, in a comparative study of 100% crops.
In a more practical setting, and especially without comparison, any difference between the 2 will not be noticed.
I use a Rokkor 58/1.2, also, and really appreciate having it. For some reason, the OOF specular highlights are larger and more diffuse than a f/1.4 or f/2.0 50mm lens at the same f/stop (say f/2.0 & f/2.8), not to mention f/1.2. And, herein lies the point, the apparent sharpness is much greater with the 58/1.2, because of the speed and probably the extra 8mm focal length.
