Strange issue with Fuji 35mm 1.4 lens

gad-westy

gad-westy

Messages
6,601
Name
Graham
Edit My Images
No
Hi all. Hoping for some assistance. I sold a lens to @tijuana taxi and he's encountered a strange problem. Hopefully you can help us resolve this one otherwise it'll be refund time.

tijuana taxi has noticed that at f/5.6 (but not other apertures), the lens doesn't focus properly and the frame appears darker when viewed. All other apertures are behaving normally. This behaviour happens on more than one Fuji body of his. Seems to be something that has developed within the last few days as my lightroom catalogue has several shots taken at f/5.6 on 7th Feb with this lens and they look great.

I think we're both hoping that there is a simple, and hopefully easily fixed explanation!

Anybody able to offer any insight?
 
Last edited:
Thanks for all the suggestions
Will try the firmware and clean the contacts tomorrow, very strange, don't think its noisier, will check that too though

One test I did was focusing on writing on a slug pellet bottle approx 4 or 5ft away, fine at 2.8 and 4, but darkens and unsharp at 5.6, ok again at 8. Its not black and totally blurred, but noticeably worse at just this one aperture, thinking it has to be the aperture ring
Never seen anything like this before, same effect when focusing on a small conifer at about 30ft away, all these are tripod mounted with remote release

Will try at 1/3rd stops tomorrow, really driving me nuts, must say Graham has been very good about it, hoping for a solution really so I can keep the lens
 
Last edited:
Have emailed Graham, but basically all the above suggestions have been looked into and are ok, good ideas though.

My theory is the aperture ring indents are slightly worn at the f/5.6 area and its not spot on unless positioned in exactly the right spot.
Could be talking from my butt, but does seem the case, wonder whether that would explain the symptoms?
 
Have you tried setting the lens to auto aperture then fiddling with the shutter speed to get f/5.6 as the aperture?
 
No I haven't, guess that would prove my aperture ring theory, will give it a go thanks Nod.

Notified Graham I would like to keep the lens whereupon he very kindly offered a goodwill payment thus reducing the asking price.

Fully expect to use the lens wide open most of the time, but its very odd how iq diminishes at f5.6 and to a lesser extent at f8, improves again at f11, most peculiar
 
Got to be worth a try!
 
You must log in or register to reply here.
Back
Top