New 70-200 f4 L IS, Slow focusing.

I have just had delivery of a new canon 70-200 f4 L IS, its tack sharp and the IS works very well, but i am finding the focusing very slow when compared to all my other USM lens, even my 100mm macro focuses from minimum focus to infinity in a split second, i think this new lens will have to go back to Canon? Has anyone else experienced slow focusing with this lens?

Try playing with the distance switch,set at 1.2m to infinity mine is a bit slower than when set at 3m to infinity.

My copy is fast as hell, indeed it spoiled me for my other L lenses. Might be worth having Canon have a look it or swapping it out with your retailer if you can.

The AF speed slows down at longer focal lengths since DOF is smaller you will see the DOF in the view finder just as fast. They do this to increase accuracy. It also have a longer though then say the 17-55mm or 85mm F1.8 so it appears slower from one extreme to another. But normal AF use they are quite similar. Try doing the test at 70mm and then 200mm. The AF motor slows down quite a bit.

Nick

Have you tried it outside? In good light the lens should focus extremely quick

Thank you for your replies, yes have tried it outside with my 1D Mk3 and 5D Mk2 and still sluggish and slow focusing, Amazon are now sending a replacement so hopefully i will get a better copy this time.