waremick Loc: New Hampshire

I have a new Sony A77 that seems to be hard on Sigma lens focus gears per what I've read in reviews. My lens ( DG Macro 70-300 ) stripped after only a short time of use. It is under warranty. But my question is .. How permanent is the 2012 Sigma warranty repair of this problem? Are there any other lens brands that this camera body seems to also be the "kiss of death" on? If I get a repair what different must I do, when using, to avoid this problem again. Lens destruction in the field does not make me happy. :( Please help, I like this lens / camera system but my budget doesn't allow many mistakes.
Thanks Bill R.

snowbear

If nobody here can answer, you might want to check with Sigma:
http://www.sigmaphoto.com/service-support

chapjohn Loc: Tigard, Oregon

FYI Sigma lenses on my A500 do not display this problem. I would talk to Sigma to get more information.

umpquafisher Loc: now in E. Central Florida

I use a Sony A290 for most of my work, and both a Sigma DG 70-300 and a Tamiron Di 70-300. Within a few months the Sigma destroyed the internal (drive?) gears and was repaired by Sigma on warranty. Now, after using the Tamiron only a few months, it too is grinding internallly. Well, they are not the BEST lenses and I don't know if Sigma will continue to repair the lens under warranty, should it become worn out again. I now turn the camera off/on in with the lens in manual focus mode, then switch the lens to auto foucus. This reduces, but does not eliminate, the grinding. BTW, I get identical results with both these lenses and am wondering if the manufacturers use the same blueprints to build them.

bawlmer Loc: Baltimore, MD

I have an A55 with both a Sigma and Tamron lens and I've never experienced this problem with either of them. I'm trying to get my head around how the camera could be at fault since the driving motor is contained in the lens itself. The camera only provides the power.

waremick Loc: New Hampshire

I have had the same thought about this lens. The camera only supplies power via the contacts. I have noticed on reviews that there seem to be a high and low seek auto-focus speed. This seems to be limited in the camera body by the switch low on the front (MF,C,A,S) which must switch in out resistance to control the focus motor speed. A recent talk with Sigma tech. dept. gives their take on this symptom ... this front control should be manual (MF). This controls the lens. The camera multi-switch (Auto, P,A,S,M) should then be able to switch via the (AF/MF) button on the back. This seems to work. This lens is now able to function more or less properly, but still is in need of a gear replacement. I blame most of this on inadequate information in the instruction materials of both the camera and lens.
Bill R.