Does a lens have a sweet spot

[pyterps]

Does a lens have a sweet spot where you will get the best image? Lets say I have a 70-200L 2.8. Is there a place ie...150/F10 that will give the best result.

If so how do you go about finding the sweet spot.

[mdr]

Take lots of pictures at all different combinations you can think off and look at the results. At least with digital, you don't have to develop 27 rolls of film.

[RockOne]

Does a lens have a sweet spot.....just taste tested mine, and it's savoury :-).

In principle there should be a sweet spot.In practice I think that with a lens of the calibre of the 70-200L you could be reasonably confidant of getting a good image at any setting. I'd say just set the lens as necessary to get the desired shot/effect, and don't worry too much about the sweet spot. In reality if the lens sweet spot is at f11 (for example), but you are in am indoor arena shooting sports for instance f11 is about as much use to you as a chocolate teapot (and the quality difference is probably not extremely different to 99% of eyes)

[ron chappel]

Here is a comparison test of the 80-200 L (among others) that shows lenses at different focal lengths and apertures
http://www.slo-foto.net/reviews-56.html

Sadly the test doesn't compare different focal lengths at similar magnification so you'll have to judge consistencey by how they compare to each other

As rock says,the 80-200 L is one of those lenses that have a very wide sweet 'spot'.I assume most L lenses would be that way.
I remember from experience that the canon 100 macro is razor sharp from about f4 to f13 'ish.

Alot of the consumer zooms have narrow sweet spots.Something like the 18-55 typically sharpens up alot once stopped down several F stops.It's also sharper one end of the zoom...but i can't rem which end:o
The 75-300 models are inevitably softer towards the long end and allmost NEED to be stopped down to f8-11 to get good results there

[chtgrubbs]

Sure, all lenses have sweet spots. The best quality lenses will be more consistent over their range of focal lengths and apertures, but will still have one focal length and aperture that's better than the others. Usually it is near the middle of the zoom range and somewhere between f/4-f11 for the aperture.

[pyterps]

Thanks a lot for all the help. Not sure why I used the lens example I did as I only dream of getting one. What I have is the standared lens that came with the Digital Rebel and a 75-300 4.0-5.6. So on the zoom lens I should get pretty good shots in the middle?