canon 70-300 f4 is
 

hi
has anyone used this lense??

in 2 minds whether to go with the 70-200L or 70-300 f4 is (for the longer reach)
read quite a few reviews and the pic's/reviews seem good about both, i know a few of the ooplefruits have used the 200L and wondered if anyone has tried the 300 f4 is?

thanks

I've used both, although on different bodies. I have used the 70-200mm f/4.0 L on a 20D and 1Ds and the Canon 70-300mm on a 350D.

What I can say, the 300mm is much nicer then the Sigma equivalent. I went to France at the start of year with Phil from Neobuggy to cover a race and he had a 300mm Sigma lens, and it was noticeably slower then the Canon one. Not really important, but noisy too (compared to Canon's silent USM). Not a bad lens, but I ended up borrowing his 200mm L, much nicer.

The L lens is nicer, I think there is no doubt there. Less distortion with the photo, not that the Canon 70-300 is bad, I got nice results with both, but when you look at the photo closely there is a difference. Another thing, the 70-300 is actually f/4.0-f/5.6 if I recall, this means it will be slower at the full zoom range whereas the 70-200 is constant f/4.0.

Another consideration (sorry I know I can type forever) if you go for 40D or 450D, they are both APS-C sized sensors. This means you get a 1.6X cropping factor compared with a full frame, which makes the 200mm effectively 320mm compared to people with full frame cams. So have that in mind when reading reviews if the person is using a full frame.

I always find 70-200mm plenty long enough on an APS-C camera, and it's even a little lighter then the 70-300mm. So my vote would be on the top notch L glass, there is a reason it's so popular I think :)

thanks jas