Canon Lens "sweet spots"

[AverageJoe]

Ok, I've read from numerous sources that some lens perform better at specific F stops than others. I'd like to see if people could provide some insight based on their experience.

 

[AverageJoe]

For me:

Canon 50mm f/1.4 best F stop is at 2.0 without a doubt.

Canon 17-40mm L best F stops have been at 8 and 11

Canon 10-22mm EF-S best F stops have been at 5.6

 

[CxThree]

For the most part, stick to F8 and F11 on most lenses. Thats a fairly safe range across most glass.

 

[Dao]

Lens review sites such as photozone.de has information like that. i.e. EF 85mm F/1.8 lens has the highest MTF at F/5.6

 

[Big Mike]

One rule of thumb is to avoid the extremes for optimum quality. In other words, most lenses are better when stopped down a stop or two from wide open...or open from the minimum aperture.

I did have one photography instructor who said that it was proven that F8 was the best aperture to use for highest quality...on any lens. I'm not sure I believe that, but F8 to F11 is usually a pretty safe range to stay in.

 

[AverageJoe]

I'm more interested in personal experiences as opposed to reviews, what have You found works best?

 

[ErectedGryphon]

This topic is very diverse, I have experienced different results based on gear configurations. On my 5D with my 28-135mm I get good results with all stops, but my "sweet spot" as you coined it, is at around f/6.3. The same lens on my father's 30D and the "sweet spot" is every thing below f/18, I would guess because of the smaller sensor size. So as you can see from my experience, it depends on both the camera and the lens combo.

 

[AverageJoe]

Thanks ErectedGryphon, that's helpfull.

 

[Big Mike]

My 'personal experience' is that I rarely worry about which specific aperture to shoot at for quality. Instead I choose the aperture based on the DOF that I want, and use good technique to optimize the quality of the image.

For example; a photo that is shot at F22 using a tripod, remote release, mirror lock up and careful focusing, will probably be sharper than a photo shot hand held at F8.

However, if I know that a lens has a specific weakness, I might avoid that. For example, I rarely use my 50mm F1.8 at F1.8.

 

[gsgary]

300mmF2.8L sweet at any F stop

 

[mtfd635]

Personal experience - I agree with Big Mike. I set the f stop for the shot, and a tripod is most useful n effective 'accessory' for ensuring IQ.
I have not found particular apertures to be problematic.
Shooting 40d & 30D with a mix of Canon L & EF-S, Tamron & Sigma.
I do not deny sweet spots exist, perhaps my technique just effectively works around it.