Front focusing

Don Martz 4:43pm, 3 May 2012
I have taken this lens in under warranty and had it returned still front focusing ...

I do get some amazing pictures with this lens, but I have to compensate and shoot with a much larger depth of field than I would normally to overlap the front focus otherwise i would have a 0-5% keeper rate.

For me this is not an f2.8 lens because it does not focus even close to accurately, I have taken to manually focusing the majority of the time.

I am taking it in to get repaired ..again on the 10th ..and i am going to request that it be replaced I know Sigma is good about that in the states... but here in Canada it gets repaired by a 3rd party company contracted to repair them.. and i do not know if they have the authority to replace them.
jadlem 5 years ago

I have the same problem with mine, it's going back to Sigma UK in a couple of weeks. Was your repair successful? Was it replaced?

AJSchot PRO Posted 5 years ago. Edited by AJSchot (member) 5 years ago
i have the same with mine, even after adjusting my focus with microadjustments it still has a front focus of 1cm @ 200mm
i found it rather big. Strange thing.. when i use the 2x it is perfect on focus @ 400mm

Also tested the lens with focal plus, and ti have to put it on back 24 but i can not set it higher than 20. More people having a big frontfocus at 200mm?
Icebergovich 5 years ago
I have different focusing at different focal lengths.

At 70mm the focus is somewhat front, but at 200mm it has back focus.

So if I set the compensation for OK focus at 200mm, then I have the same large front focus at 70 mm.

What should I do?
D'artist2013 4 years ago
I have the same issue with my new 70-200 f2.8 os
Front focus in wide aperture .I shoot portrait .frist day of use was ok im so happy with the result during my street photo testing.but got noticed when i shoot model the following day i found it intermittent focus issue in the aperture, shutter speed and distance to subject.intermiitent is sharp to soft i bring the lens to sigma singapore for calibration, after calibration i use the lens again for model shot and still the same.headache for this I bring it again and the techn say they will replace the os im hoping after replacement of os will solve the problem...just hoping because I tried it with os off still sharl to soft I get.
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