06-25-2010, 01:04 AM
[quote name='wim' date='23 June 2010 - 06:45 PM' timestamp='1277282755' post='664']
For any other options, I was thinking of having custom created lenses - an expensive option.
[/quote]
Good point. From the inquiries I've made, I guess a fast wide lens of that sort should cost around USD 40K if you get them to do the designing and the engineering. If you gave your own design it should cost probably 1/3 to a 1/2 less than that.
[quote name='wim' date='23 June 2010 - 06:45 PM' timestamp='1277282755' post='664']
Regarding wide open sharpness: I do believe my copy of the II is slightly sharper than the Mk I copy I had, but that may also be influenced to aforementioned AF problems. Field curvature with the II certainly is way less than with the Mk I: for some brainstorm sessions at work I did photograph white boards in order to have a record of what was scribbled down, and I could get virtually all of the board sharp in focus, frame filling, even at F/1.4. That really amazed me.
[/quote]
Hmm... I don't use AF when testing lenses for optics. It was again one of those full blown technical comparisons involving tripods, magnified LV, etc. The Mk I might have been very slightly sharper, if at all, only in the center. Corners went straight to the Mk II. Also when stopped down, the Mk II corners are much much cleaner in terms of CA than Mk I corners. As for the field curvature, they don't show much at close distances, most of the time. What I shot was a big wall that was around 15-20 feet away. The way I figured the Mk II had a bigger curvature is by examining the differences focus between center-focused shots and corner-focused shots. Mk II, of course, showed the biggest difference to me.
<img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' />
GTW
For any other options, I was thinking of having custom created lenses - an expensive option.
[/quote]
Good point. From the inquiries I've made, I guess a fast wide lens of that sort should cost around USD 40K if you get them to do the designing and the engineering. If you gave your own design it should cost probably 1/3 to a 1/2 less than that.
[quote name='wim' date='23 June 2010 - 06:45 PM' timestamp='1277282755' post='664']
Regarding wide open sharpness: I do believe my copy of the II is slightly sharper than the Mk I copy I had, but that may also be influenced to aforementioned AF problems. Field curvature with the II certainly is way less than with the Mk I: for some brainstorm sessions at work I did photograph white boards in order to have a record of what was scribbled down, and I could get virtually all of the board sharp in focus, frame filling, even at F/1.4. That really amazed me.
[/quote]
Hmm... I don't use AF when testing lenses for optics. It was again one of those full blown technical comparisons involving tripods, magnified LV, etc. The Mk I might have been very slightly sharper, if at all, only in the center. Corners went straight to the Mk II. Also when stopped down, the Mk II corners are much much cleaner in terms of CA than Mk I corners. As for the field curvature, they don't show much at close distances, most of the time. What I shot was a big wall that was around 15-20 feet away. The way I figured the Mk II had a bigger curvature is by examining the differences focus between center-focused shots and corner-focused shots. Mk II, of course, showed the biggest difference to me.
<img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/smile.gif' class='bbc_emoticon' alt='
' />GTW