Sigma 10-20 autofocus problem

[oldhat]

Problems when using a Sigma 10-20 wide angle zoom lens on an Olympus E-510. The autofocus often fails to work; the red spot only appears if using one AF-frame, not Auto-AF.
The information display on the screen shows shutter speed but has a blank -.- where aperture setting should be shown.
There is no problem with three other lenses, Olympus and sigma, on the same body; and the lens is set to AF, and the contacts have been cleaned.
It's still under warranty, but any suggestions? anyone had a similar problem?
Gerald

[photo_owl]

Re: Sigma 10-20 autofocus problem

combined your symptoms scream 'lack of electronic connection between lens and camera'.

1. keep fingers well clear of lens release button when mounting lens - twist to positive click.
2. keep fingers clear of lens release button when shooting
3. use a pencil eraser to clean the electronic connections on the lens mount.

[oldhat]

Re: Sigma 10-20 autofocus problem

Thanks for the advice ... but none of that makes any difference.

I'm glad I bought it locally not on the net - I'll take it back to the shop tomorrow and ask for it to be sent back to Sigma under warranty ... unless anyone has another suggestion !
Gerald

[ringneck]

Re: Sigma 10-20 autofocus problem

I have have similar probs with kit 14-42 and 40 150 lenses in the past and I too think it was to do with connection trouble.I had to re-fit the lenses a few times and then it came back on,.Also on one occasion it had not clicked in all the way when fitting it.
On Sunday the focus WENT on my new Sigma 135-400 in the middle of a session and then it was the fit...god only knows how it became looser while using it....

Cheers
Keith