Sharpest aperature for various lenses.

I know that lenses tend to vary on crop bodies and full frame bodies.
I have a 5d2 and t2I.
But the various lenses have their sweet spots.

What do you all find as the sweet spot aperature for various lenses?

Thanks

Normally a rule of thumb is that most lens sweet spots will be about two stops down from wide open. However, you really can't go wrong with shooting around f/8.

Check here: http://www.photozone.d​e/Reviews/overview

I have seen the various reviews on the lenses, but I wanted to know from personal experience what folks thought was Their favorite sweet spots for various lenses.
Say, the 24-105.
What gives YOU the best IQ.
Do you have a go to aperature?

I have the above lens and the 7-200 2.8 II
I also have a 17-40 and a 15-85 for my t2i's.
I have a 85 1.8 and the nifty fifty.
There are a lot of great primes such as the 35, 50, 85 and 135.

What do you folks find as the sweetest of the sweet spot for aperature.

Thanks

Agreed. Usually 2 full stops down from wide open. Obviously exceptions to the rule

A stop or two from wide open gets you in the ballpark. Anything more specific is really just splitting hairs.

There's no easy answer. I have the same 5D2/T2i combo. First consideration is the body. The higher the sensor density the more susceptible to diffraction. So the 5d2 starts getting impacted at f8 or above, while the T2i starts getting impacted below f8. Someone with more knowledge than me will correct this...but this is my basic understanding backed by some real-world experience.

Second consideration is the lens. x_tan mentioned photozone. An excellent resource for researching resolving power for the center, edge and corner of different lenses (on different bodies in some cases). You will find that, for some lenses, as aperture increases, center sharpness decreases, but edge sharpness increases, yielding an overall better image. The more you look, the more you'll realized, there's not a standard pattern.

Other lens considerations include idiosyncrasies like field curvature and ability to manage flare.

If I put forth a general rule, I totally agree with most comments here...two stops above the lens's widest aperture is best for the lens and likely fits within the body's sweet spot as well. Just be aware that this is not a simple black-or-white issue.

For real measurebators who simply have to know the exact 'sweet spot' for each of their lenses - the latest version ofFoCal Pro has a utility to measure exactly that - automatically.

Great optics have very good performances wide open, really near their "sweet" spot...

Generally 2 or 3 stops are the best in theory but do you need these apertures ? I often shoot wide open for portraits or closed apertures (f11-f16) for landscape or macro, to adapt the depth-of-field / amount of bokeh but not really at the sweet spot (f/5.6 by example) of the lens... of course it's better to know the limits of your optics, but modern "good" optics should give good results at each aperture.

Titi

When in doubt f8

The sweetspot will typically be somewhere between f/5.6 and f/11. I always test every new lens using a test target for just this kind of information. I want to know how to use a particular lens to get the very best out of it.

"Optimal" aperture according to FoCal 1.3.1 and my Sigma 50mm/5DmkII would be F/5.6

Good stuff folks.
I guess it varies from one persons 24-105 to another.

Thanks

KarlGB77 wrote in post #14214619
I guess it varies from one persons 24-105 to another.

I don't think it will vary much from lens to lens. Where it can vary is at different focal lengths, and sometimes even at different focus distances. FF vs crop camera can make a difference too.

To me, it depends upon the lens in question. If I am purchasing a fast aperture lens- like a f/2.8, I sure as heck don't want to stop it down to f/5.6 or f/8 to get good results with it- heck- I may as well have gotten a kit lens then.. When I buy a prime- like a f/1.4, again, I don't want to have to shoot it at f/4 for optimal sharpness - it should be, imo, sufficiently sharp either wide open, or within a stop of being wide open.. If it's not, again, my opinion, it should be going back. Otherwise, what's the point? Sorry, rhetorical question there. Just my opinion.
Determining the point where a lens is sufficiently sharp- well, that's just a matter of a few test shots at different apertures. My Sigma 70-200 OS is sufficiently sharp starting around f/3.2.. If I choose to stop it down to f/4 or f/5.6 - for DOF- that's fine, but I should not have to in order to get decent sharpness out of a pricey piece of gear.