# Sweet spot of EF 70-200mm f/4l



## jamesino (Jul 19, 2008)

What is the absolute sweet spot, in terms of a focal range and aperture combination, for the Canon EF 70-200mm f/4l USM (without IS)?

Would it be 135mm at f/5.6?

EDIT: Sweet spot as in the area where the IQ is the highest.


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## reg (Jul 19, 2008)

It's already an L lens, why are people so obsessed with this stuff?

In the time it takes to do resolution charts and find out how many degrees of blah blah blah and chromatic abberation and this and that and the other...

YOU COULD HAVE BEEN OUT SHOOTING!!

See also: I don't know.


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## prodigy2k7 (Jul 19, 2008)

On the 70-200mm F/2.8 IS USM (different lens) it is at 100mm F/5.6 I believe 

Maybe they are similar?


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## Big Mike (Jul 20, 2008)

Pro lenses, and especially pro telephoto lenses are often designed so that they are very good with a wide open aperture...as that is where they will often be used.  They still might be a little better when stopped down one or two stops, as that is typical for most lenses.

I've also heard that F8 is a very good aperture for most lenses.

With a lens like that, I wouldn't worry about it.  It will be exceptionally good throughout the range.  Concentrate rather on other factors to improve IQ...like using a tripod and MLU.


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