A700 & stripping gears.

[CBA100]

I've decided im due for a long awaited upgrade and the A700 seemed the likely upgrade...however...

I've been reading ALOT of reviews regarding Sigma lenses stripping on the A700.

Is this any particular Sigma lens?


I've recently part-exchanged 2 of my Sony lenses for a Sigma 18-50 F2.8 EX DC, and i'm a little concerned about this lens and the gear stripping problem

 

[Marc]

It was caused by the cheap plastic gears that sigma used combined with the very powerful AF motor in the Sonys (I've heard tales of it happening to other models, not just the a700).

Had it happen twice (105mm and 24-70), both under warranty. Sigma repaired them without an issue, the latter with new stronger gears. I believe the current crop of sigma lenses are made with the stronger gears so it may no longer be an issue.

The a700 does have the facility to set the AF to Slow and it doesn't appear to make that much difference to the AF speed.

 

[CBA100]

It was caused by the cheap plastic gears that sigma used combined with the very powerful AF motor in the Sonys (I've heard tales of it happening to other models, not just the a700).

Had it happen twice (105mm and 24-70), both under warranty. Sigma repaired them without an issue, the latter with new stronger gears. I believe the current crop of sigma lenses are made with the stronger gears so it may no longer be an issue.

The a700 does have the facility to set the AF to Slow and it doesn't appear to make that much difference to the AF speed.

Thanks Marc.

With my Sigma being no longer under warrenty (its the 2005 67mm discontinued version), its a little more concerning. Its a case of risking it OR selling it on for another lens :shrug:

I have read about the speed setting, but havent read anywhere that could confirm this doesnt happen if the A700 is set to slow AF.

 

[Faldrax]

It's something I've looked into (since I have an A700).

The biggest 'victim' in the 70-300 APO, but it does happen on other Sigmas as well.

Generally the advice is to set AF to slow which seems to reduce the problem significantly.

It is also much less common with wide angle and EX series lenses, and, of course, HSM lenses are fine.

The 18-50 EX DC should be OK I would expect, particularly with Slow AF.

Of course, no-one has done a scientific test, this is all based on people reporting what has broken (and what has not).

 

[CBA100]

It's something I've looked into (since I have an A700).

The biggest 'victim' in the 70-300 APO, but it does happen on other Sigmas as well.

Generally the advice is to set AF to slow which seems to reduce the problem significantly.

It is also much less common with wide angle and EX series lenses, and, of course, HSM lenses are fine.

The 18-50 EX DC should be OK I would expect, particularly with Slow AF.

Of course, no-one has done a scientific test, this is all based on people reporting what has broken (and what has not).

Thanks for the info Jonathan.

At the moment i couldnt afford to have to replace the 18-50mm if anything should happen to it, and i've read of Sigma's being stripped within days or using them on an A700.

I think (instead of risking it) i may be more inclined to PX the Sigma for something like a Tamron 17-50mm