Sigma lens AF issue

[Toggerman]

Hi all,

I've been having problems with my kit lately. I shoot motorsport mostly and use a combination of D700 with Siggy 70-200 f2.8 HSMII, and a D300 with a siggy 100-300 f4. A few weeks ago I started having problems with the 100-300. It'd be fine in the morning but as the day went on it would randomly stop focussing, the last time it happened it was ~15 times in the day. Detaching the lens and reconnecting it would fix it. I can't test it on the D700 as the aperture lever is broken.

On the weekend I was out shooting a 2 day event and the 100-300 was fine on both days. On the afternoon of the second day I had the same thing happen with the 70-200 on the D700, it stopped focussing twice.

I have another month of warranty left on the 100-300 but now I've had it happen with a different lens on a different body I'm not sure what's going on.

Has anyone else had anything similar happen? Any ideas on the problem/fix?

TIA,
Scott.

 

[Bristolian]

Scott,

My first suggestion would be to give both the lens and body electrical contacts a good clean and see if that solves the problem - most likely it will judging by the symptoms you describe.

 

[Toggerman]

Hi Steve,

I've already tried that with the D300 and 100-300mm with some isopropyl alcohol with no joy. I'll give it another try though with some eclipse fluid maybe. I wouldn't be surprised if the D700 was just dirty as I swap lenses on that quite often (the 100-300 is almost glued onto the D300).

Cheers.
Scott.