Is my Canon 24-70 f/2.8 II ok?

[COBRASoft]

Hi,

I bought the great Canon 24-70 f/2.8 II some weeks ago. Above 35mm it is a superb lens, but at 24mm f/2.8... I'm not so sure. So, I micro adjusted the lens using Focal and did some tests afterwards.

Attached, you can find the PDF for the 24mm focus test. At 70mm, the chart shows a straight horizontal line from f/2.8 till F/8.0 (more or less). At 24mm f2/8, it is kinda blurry until I go to F/6.3. The lens is also sharper from 50 to 70mm f/2.8 than 24mm.

Now, I'm wondering, do I have a bad copy of the lens or is this normal? When I look at DxO for this lens, it should give me a better result at 24mm.

Greetings,
Sigurd

 

[zlatko]

I'm not sure it makes a difference, but your shutter speeds are very slow in the pdf test report. I try to run FoCal with a shutter speed of at least 1/100th -- just to avoid any camera shake effects, even with a sturdy tripod. You can manually raise the ISO in the preferences to get a higher shutter speed. Also, add more light.

 

[Loswr]

Also, add more light.

+1, I like to give FoCal at least 10 EV.

 

[pwp]

I agree, you need to get the shutter speeds up for meaningful test results. At the very least, test with the camera on a good tripod and use a cable release.

FWIW my copy of the 24-70 f/2.8II is so good I've sold my 24 f/1.4II, my 35 f/2 and my Sigma 50 f/1.4. It comfortably outperforms these three primes.

-pw

 

[COBRASoft]

Ok, I'll redo the test tomorrow with more light.
Nevertheless, I still don't understand why the curve has this shape. At 70mm (same light and settings), the curve is a straight line for the first 3 full stops. According to DxO, the lens should be very sharp, even at 24mm f/2.8.

pwp, is your lens also noticeable sharper at the tele end compared to the wide end?

 

[pwp]

pwp, is your lens also noticeable sharper at the tele end compared to the wide end?

No, not noticeably. With most zooms there will be some variation from the wide to tele extremes.
I'm no pixel peeper, but what I do notice is consistently, usefully sharp shots and happy clients.

-pw

 

[Mt Spokane Photography]

Also, add more light.

+1, I like to give FoCal at least 10 EV.

Yes, the AF system does not like lower light levels and loses consistency. ev 10 or more works better.

 

[mwh1964]

Your lens should be performing flawlessly at 24 mm. If not satisfied return it immediately.