Comments on: Canon 24-70 f/2.8 II Resolution Tests

By: Andy

Andy — Mon, 20 May 2013 21:15:49 +0000

Hi Roger,
I’m getting awful flare, even when the sun is not in the frame and quite high.Its not even attractive flare.

Is there any thing that can be done apart from trying to shield it?

Regards,

Andy

By: Andy

Andy — Sat, 02 Mar 2013 23:03:22 +0000

Thanks Roger for all your help.
Ill get In touch with Canon Uk. Mind you after my last experience with them I won’t hold my breath. It took them 3 attempts to calibrate my bodies/ lenses. So I’m not sure…Can I ship it over to you guys….
Cheers,
Andy

By: Roger Cicala

Roger Cicala — Sat, 02 Mar 2013 17:17:35 +0000

Andy,

It certainly can be. Canon can adjust them back to where they should be. Just be specific where the problem is – which focal lengths, what part of the lens at what aperture, etc.

By: Andy

Andy — Sat, 02 Mar 2013 17:04:15 +0000

Hi Roger,
Last question, promise.
My copy isn’t, so can it be brought up to spec ?
Thanks,
Andy.

By: Roger Cicala

Roger Cicala — Sat, 02 Mar 2013 03:27:00 +0000

Andy, at f/5.6 it should. At f/8 it would be very close. The sides should be at least as sharp as the center.

By: Andy

Andy — Sat, 02 Mar 2013 01:12:55 +0000

Sorry Roger, I don’t think I was very clear in my previous question. What I meant to ask, should at f8 or 5.6 (50mm) give you the same sharpness at the centre edge (left & right) as in the middle of the frame?
Thanks again,
Andy.

By: Roger Cicala

Roger Cicala — Sat, 02 Mar 2013 00:46:43 +0000

Andy,
One thing I will note is the 24-70 II is going to be softer in the center at f/8 than at f/5.6. It is at maximum sharpness at f/4. After that diffraction, while mild, is definitely going to be present. That’s unusual to see at this aperture but most lenses are getting sharper stopped down and that more than offsets diffraction. The 24-70 II is not getting sharper stopped down past f/4 so all you see is the diffraction, at least in the center.

By: Andy

Andy — Fri, 01 Mar 2013 22:07:39 +0000

Thanks for the reply Roger.
I thought not also.
I picked up another copy today and it is a lttle better across the frame, but still not as sharp as the centre @ f8.
With the second copy, colour moire is stronger and also red CA on the chart I am using for testing. Sorry to ask, but is this normal? In a way I hope so, as I don’t think the shop will let me have another copy. I wish I could send you a sample to look at.
Cheers,
Andy.

By: Roger Cicala

Roger Cicala — Tue, 26 Feb 2013 21:16:28 +0000

Andy, definitely not. Sounds like it may be a decentered copy. It should be tack sharp across the frame.

By: Andy

Andy — Tue, 26 Feb 2013 19:01:39 +0000

Hi Roger,

I’m finding with my copy that even at f8 a little soft towards centre edge of frame when taking full lengh portraits @ 50 mm.
The body will be pin sharp but the face is definitely a little soft, even using live view to focus on the face.
Should this be the case?
Cheers,
Andy.