Sigma 35mm 1.4 beware of focus issues close to infinity

Started Jun 14, 2013 | Discussions thread
mevbo Senior Member • Posts: 1,217
Re: Sigma 35mm 1.4 beware of focus issues close to infinity

Daniel wrote:

When I received my Sigma 35mm F1.4 Arts lens, I was impressed with the optics after I fixed the front focusing with MFA setting of +13. However, after a couple months of use, I noticed my landscape images weren't as sharp as when I was shooting people. When my Sigma USB Lens Dock arrived, I played with fine tuning my lens for hours. Now, I noticed there is something wrong/defective with the far end focus from 2m to infinity. At 2m end, MFA setting of +13 is needed but at infinity end, MFA setting of +7 is needed. Because 2m to infinity are in the same MFA section for this lens (using Sigma USB lens dock), I can only fix either 2m side or infinity side but not both. Worse yet, I noticed that the focus is not consistent, especially worse toward the infinity end. If I set my Canon 5D Mark III to AI Focus mode and try to focus on a stationary high contrast object close to the infinity end, focus will hunt non-stop. This problem still exist near the 2m end but not as bad. Everything else from 0.3m to 2m is working fine with consistent focus after applying MFA.

Anyone else noticed focus problems from 2m to infinity?

1. 2m and near infinity focus need different MFA settings.

2. Focus is not consistent, hunts in AI Focus mode more so near the infinity end.


I did in body ma at the"gap" between infinity and the first dock focal length.   Then I adjust the 4 dock points.   Works well.  

 mevbo's gear list:mevbo's gear list
Canon EOS 5D Mark III Canon EF 85mm f/1.2L II USM Canon EF 70-200mm f/2.8L IS II USM Canon Extender EF 2x III Canon EF 24-70mm f/2.8L II USM +3 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow