emair From Switzerland, joined Sep 2006, 110 posts, RR: 3 Posted (2 years 4 months 1 week 5 days 13 hours ago) and read 5101 times:
I have an issue with my Sigma Sigma 170-500mm F5-6.3 DG APO and I hope you guys can help me out.
Here is the issue I'm having with it. It doesn't matter what setting I set and it still doesn't focus when is out more than 300mm on a far away object however, If I'm close to an object and it's all the way out (500mm) it does focus. For the past years this lens has been working very well. Had this issue since two years now.
I believe the problem is inside the lens, I think the "focusing ring" isn't working properly however, I have never open by myself a lens and try to fix it, I might be completely wrong.
oly720man From United Kingdom, joined May 2004, 6997 posts, RR: 11
Reply 1, posted (2 years 4 months 1 week 5 days 2 hours ago) and read 5044 times:
The lens does what the camera tells it to do. It's more likely that with things far away at the higher focal lengths you're not getting the contrast for the AF to work, especially if it does work when things are closer. This may reflect a deterioration somewhere in either the lens or camera and would require one or other to be serviced. It's not something you could do yourself.
emair From Switzerland, joined Sep 2006, 110 posts, RR: 3
Reply 2, posted (2 years 4 months 1 week 5 days 2 hours ago) and read 5041 times:
You are right saying the lens does what the camera tells it do however, I tried this lens on my other camera, just to make sure the issue was not on the camera, and I had the same problem. This lens used to be fine however, is 7+ years old, that might be a factor, just wondering if someone had the same issue..