Canon Telephoto Lenses

[Quintin]

Hi,

I've been comparing two lenses recently:

EF 70-200mm f/2.8 USM IS
EF 70-200mm f/4 USM IS

They have exactly the same zoom range, but the f/2.8 is faster, larger and heavier. I was planning to go for the f/2.8 all the way, until I read reviews of the same lenses on Photozone:

EF 70-200mm f/2.8 USM IS
EF 70-200mm f/4 USM IS

The Digital Picture is my go-to site for info on lenses, but a friend recently pointed me to Photozone, which goes into much more technical depth. Photozone insists that the f/4 is the much better decision, citing much better image quality.

Can anyone offer some insight on the difference between the two?

Thanks!

[digirebelva]

I have also heard that the F/4 is the sharper of the 2, I guess it comes down to how much shooting indoors in low light you are planning to do..Outside of that, I am not sure you are going to see that much of a difference in IQ to use that alone in making your decision. I have the F/4 non-is version and when its on its sharp no doubt. I'll let the photogs with the F/2.8 chime in with their experience

[Canon Bob]

I have both the 70-200 IS models. The f/4 IS has a later optical design and is indeed a little sharper although I doubt that you'd see it in real world shooting with both lenses at f/4.
There are clear advantages to the f/2.8 IS in that you can shoot moving objects at a higher shutter speed if necessary (the IS won't help you here) and also the focus accurracy on most bodies will be better....f/2.8 lenses are focussed to within 1/3 depth of focus as opposed to simply within the depth of focus for f/4 lenses....that fact alone could eliminate the f/4's sharpness advantage.

I would advise that you base your decision on cost, portabilty and whether you would benefit from the additional stop.

Bob