Fast, accurate focus.
Building quality.

??????

This lens is the best I've ever tried. Together with my EOS 10 it gives me most outstanding picture, sharpness, color... you name it.
No sign of vignetting, in all this is for me the
ultimate lens for every kind of outdoor photografing. It's light to carry aroound in the forrest, when crawling after wildlife the small size gives me possibilities to get closer then
imagine.

Customer Service

Non so far

Similar Products Used:

Sigma 400/5.6

Build Quality
Fast AF
Almost Silent !
L Series Optics
Light

None Really

A very good lens if you need a fast yet versatile and easy to carry telephoto prime lens. No difference when wide open or stopped down that i noticed. Very good to use with flash too !

Customer Service

First Class

Similar Products Used:

Canon 400mm F2.8
Canon 600mm F4
Canon 100 - 400is
Most Useful L Lenses

Extremely sharp even wide open. Contrast and color is excellent. Small and light-weight enough to carry in a back-pack.

Built-in lens hood does not lock. Will slip back down if lens is pointed up-ward.

Excellent lens.

Similar Products Used:

Canon 75-300mm f/4-5.6 II USM.

You can't talk bad about your best friend! This lens is sharp, it has a good focus ring when you don't use the autofocus and it is lightweight. It is a very good lens if you want to be movable in the forest, like crawling on the ground to get close on animals.

1) The lens hood has to be fastened with tape or a rubber band, otherwise it will sound with a metallic "cloink".
2) The Canon white colour is stupid, to be able to use the lens for animal hunting it always has to be covered with camo tape.

Mostly I use this lens with a monopod or a homemade shoulder-butt, often with the Extender X2, and for the remaining time I use a tripod.
Closest range is 2,5 meter. If you are sitting and waiting in the bushes for something to happens and a bird touch down 1,5 meter in front of you, that's irritating. The new EF300/4L IS should have saved me from this problem, but it costs more and I'm not shure I need the "stabilize thing". On the other hand, if I had used EF 300/2:8L the closest range had been 3 meter.
At least here in Sweden, the price has fallen because of the introduction of EF 300/4L IS and the competition from Tokina and Tamron with similiar products. This has made this lens very worth it's price, and there are also lenses to be found at the second-hand market.

Customer Service

I had a focus problem, when using the manual focus ring it slipped at the distance 4-7 meter, but probably I had given the lens a smack somewhere. Anyhow, the Swedish Canon service center Pro-Flex AB fixed it fast (Thanks!).

Similar Products Used:

Cheaper Canon 100-300 zoom lenses with 5:6