Hi!
Not having Canon and just looking at MTF-curves...
My personal experience has been with Minolta 20 1:2.8 and Pentax 67 and 45 1:4.5 (?) lenses. Both these lenses were quite unsharp in the corners at apertures larger than 1/11.
I have looked at MTF curves for quite a few wide angle lenses and zooms and I would say that a very sharp drop of MTF at the corners is essentially the rule with wide angles for SLRs. I think that this is mostly due to the need of retrofocus design.
Wide angles for rangefinders (like Leica) don't have this behaviour. There are a lot of discussions about using oddball lenses like "Olympus 18 mm" and Zeiss-Jena Flektogon on Canon and that may work, but that would mean manual operation.
A lens which has a good reputation when used on Canon is the Sigma 12-24 full frame zoom, but quality seems to be uneven.
One recommendation that I would have is that you compare the four corners. If some corners are sharp and some are not it would indicate a decentered lens. If you are looking at "actual pixels" the view would correspond to something like an 1.5 m enlargement. Can you see the unsharp corners in print?
Here is the MTF for Canon 16-35/2.8 II
http://www.usa.canon.com/consumer/controll...8&modelid=14907and here is the one for the 24 TS
http://www.usa.canon.com/consumer/controll...56&modelid=7328Sean Reid has a good site on this issues:
http://www.reidreviews.com/reidreviews/It is a pay site, but I think it's worth the few dollars he asks...
Best regards
Erik
QUOTE (Lust4Life @ Mar 6 2007, 02:49 PM)
For the last 35 years I've been shooting 4x5 and Hasselblad. Using the best lenses in both formats (I class in Hassie).
Just recently I bought a new Canon 1DS Mk II with the 16-35 L, 24 L TCE and the 70-200 L Canon lenses. All purchased brand new from Calumet and B&H.
This past weekend I finally had time to run tests on the 16-35 and the 24 lenses. I am very distressed with the resultant POOR quality of these lenses compared to what I've been used to. Canon should be ashamed of these lenses!
I took a real workd scene - waterfall, rock cliffs, trees - and set the 1Ds up on a tripod. Using the remote I shot one frame of every aperture. Came home, downloaded the images into Lightroom and began to study the results.
I was disgusted to find there is no aperture for either lens that is sharp in the corners or across the borders!! Identical for both lenses.
Forget sharpening filters - it just can't be corrected properly.
Now, I do find the fidelity of the array in the 1Ds decent and I'm wondering if the 50, 100 and 150 I class lenses I have on a Hasselblad 503CW would work on the Canon. Has anyone tried this with success?
PS: I am so disgusted that I plan to add a page to my web site with cuts of the test images so anyone contemplating these lenses can have a look to see what they will get for their money. Give me a couple of weeks to get to this addition.
http://www.shadowsdancing.com