IS Problems

[bobs4c]

Some months back I went to Castle Combe to take some photos using my fairly recently purchased 70-300 IS Canon lens, using Mode 2 for panning. I went to Quarry corner and my camera wouldn't focus properly.

Didn't think much about it, thought it might be dirty contacts because it was OK when I got back home.

Today, the same thing happened - but only at Quarry. Anywhere else on the circuit the camera/lens were fine. I was a bit slow to realise that it must have been due to the very close power lines which were the only thing I could think would affect the lens. Looking through the viewfinder, you get a blurred image, switch off IS and it was fine.

Thought I'd mention it to see if anyone else has experienced such a problem.

Bob

[agent006]

I have the same lens. On my old D30 i found that if it couldn't quite focus on something (plane in grey sky etc) it would just wind the focus ring all the way out and stay there until it was givne something much closer to focus on or pulled in manually. Not had the problem with it on the 1d so not sure if it was lens or camera.

[bramley]

my 70-200 IS was ok at Quarry (well I blame my lack of talent for poor results!) but I can say you shouldn't underestimate those power lines. They had the central locking on my golf rallye twitching when I parked under them, the body was 'live' like a permanent statci shock if you touched the door, and I saw a kid hold up an umbrella as a joke, then he screamed and dropped it! I always get a headache if I spend too long at quarry so I'd suggest it is a possible cause of the problems you've experienced.