Any thoughts on where one might be able to find the front element for this lens? Where would I even search, or who might have nonfunctioning versions with a good element?
More importantly, I picked up a malfunctioning 400 f2.8 ai and have noted the following symptoms:
- won\'t quite focus to infinity
- very soft wide open, improves slowly until f11, at which point it\'s decent, but still not as sharp as my 300 f4.5 ai, while still much heavier
- switching between 2.8 and 4 seems to make no difference whatsoever in pictures, though you can see the aperture blades move accordingly
- focus is super smooth, glass is clean barring a few marks on the frontmost element
What might be the issue here, an element knocked out of alignment? Who might be able to adjust/repair it, or could I do it myself somehow? Are there some reliable guides out there for this sort of thing? Thanks a lot ahead of time, guys, I(\'d/\'ll) appreciate it!
Any thoughts on where one might be able to find the front element for this lens? Where would I even search, or who might have nonfunctioning versions with a good element?