Dazed767 From United States of America, joined May 1999, 5512 posts, RR: 50 Posted (10 years 6 months 3 weeks 5 days 14 hours ago) and read 3595 times:
I was taking photos with my 300D the other day (had a Sigma 17-35mm f/2.8 attached). In the middle of focusing, the view finder became dark, or very tinted, but then went away. It happened 2 times, but I could hear a small click when it would go away. Could this have something to do with my shutter (maybe coming down half way causing the somewhat dark view finder?). Anybody else have this problem before? Thanks.
It's been working fine since, and this was 4 days ago.
Wietse From Netherlands, joined Oct 2001, 3809 posts, RR: 54
Reply 1, posted (10 years 6 months 3 weeks 5 days 14 hours ago) and read 3570 times:
The viewfinder cannot be part of the problem... The mirror reflects the light towards the eyepiece. The shutter is behind the mirror and therefore not in the direct path of the light. Even if it would close, open, or whatever, you wouldn't see it in the viewfinder.
My guess is that your sigma closed down its apperture. Perhaps you pressed the preview button? That would cause the viewfinder to go dark.
DeVoDaVe From United States of America, joined May 2003, 2 posts, RR: 0
Reply 6, posted (10 years 6 months 3 weeks 5 days 9 hours ago) and read 3466 times:
I had the same problem with the same exact lens and determined that it was the aperature getting stuck closed. You can verify this by taking the lens off and looking through it to see of the aperature is open or closed.
The first time it happened, I was able to get it back to normal by switching lenses on my 10D. When I put the Sigma back on the camera, it worked. Everything was fine for many months after that until the problem happened again and I was unable to get the lens working at all.