24-70mm f/2.8 L not sharp.

[a.ueberbach]

I just treated myself to a new 24-70mm f/2.8 L... which for some reason does not perform as it should. Even when stopped down to 4.0 or greater, sharpness is not satisfying without some serious sharpening in Lightroom.


Compared to my other L's (e.g. 70-200 f/2.8 IS), sharpness is lousy...So far I only have checked the lens on my trusty 20d bodys using AF.





Did anyone have similar problems with the 24-70 and did you send the lens back to canon for warranty/exchange or similar?





Cheers,


Andre





A few tests...


(1) After serious sharpening, picture turned out to be good. f4.0, 1/60, 70mm at ISO 400 w Flash (crop 100%)


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(2) Another picture, fefore sharpening at f2.8... Quality sucks. f2.8, 1/60, 27mm at ISO 400 w Flash (crop 100%)


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[Benjamin]

I have been using the 24-70L for almost 2 years now and it appears to be very sharp wide-open with in-camera sharpness set to 2! Don't get me wrong though, by sharp wide-open I mean shooting portrait with a 1.6x body. Your second shot does seem to be quite soft, however, I'm not sure if this is due to a soft lens or it's not in focus.


Sometime I don't get expected sharpness from the lens when it's not focused properly. You can check the lens' focus by doing some simple tests, for example, tripod mounted and shoot newspaper on the wall, then enlarge to see if the place in focus is where you focused to.


I realize that at least these two pictures you posted were taken indoor. The lens could appear to be not as sharp when ambient lighting is not great, so instead, you can do some test in good lighting like outdoor under sun light. Poor lighting environment will somewhat affect the AF accuracy as well.


Also please make sure to use safe shutter speed to stop any kind of hand shaking or motion blur. the 24-70L does not have IS and as far as I use it I become nervous when handholding it down to 1/30s. So testing in good lighting also helps in this regard. Plus you can turn the ISO down in good lighting andlow ISOwill allow the camera to capture every detail for your benefit to determine if the lens is sharp or not. You don't want to judge sharpness at ISO3200...


Just just personal advise.[]


Ben

[peety3]

If you want a valid test, get your shutter speeds significantly faster and show us the results. Your first sample isn't even above the threshold for normal hand-holdability, and the second example could easily be influenced by subject movement.


Start with tripod, shutter speeds at one-over-(focal-length*10) or faster, with a stationary subject.

[a.ueberbach]

Thanks for your messages.


Both pictures were well in focus, as far as I know. Generally, so far all images I got from this lens needed some/or serious sharpening in the postproduction stage to apear sharp enough.As with all my other L's, I did not have any AF Problems, especially not with the faster ones. This is why I am a bit suprised about the performance of this copy. Maybe the copy is bad!?


Yep, both examples are not well chosen as I didn't have time to do a proper run to check for sharpness. Light should have been no big issue as I used a 580EX II set to +1 and ambient light was present... so even slightly overexposed.


I will post some reference pictures with tripod shortly.





1/60 is hand-holdable, at least if you do not have Parkinson's disease or a low blood sugar level at the time of the shot. ;-)
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[David Selby]

hey which camera model are you using?





are you using a flash to focus indoors? what focus mode?

[Bob]

Wat was the shooting distance for both photos?


Bob

[Dallasphotog]

I'm going to bet against a problem lens. I have the 24-70mm f/2.8 L and it can be quite sharp and clean. However, I also use a 70-200MM F/2.8 L IS USM and I forget how much shake the IS is fixing for me. I'll be shooting along at 1/60 or even 1/30 and the IS will keep things looking good, then I swap lens and BANG, my pictures suck. I'm just not that good below 1/100 off hand.


Iwould suggest a tripod test with stellar lights and about 1/1000. If the sharpness comes back, blame camerashake. If it is still soft, start looking at the lens and body.

[Cushty]

I've thought the same on a couple of shoots. I did some product shots for an Ice cream parlour which I wasn't too happy with but when i used a DOF calculator afterwards (and too late) it turned out the DOF was about the width of a razor. Even at f5.6 if you're within 5 feet of your subject at 70mm the DOF is only about 3 inches that can wreck a portrait if the AF has focused on the nose tip. Ive got the 70-200 f4L IS USM too which is a very forgiving lens that is difficult to get a bad image with.


I have had some excellent results with this lens but if you're not in the safe zone its a case of point-think-shoot rather than point and shoot. If I get a soft shot I always try to see what went wrong. Slaked lines and specs can reveal motion blur. Poor Focus and Low DOF can usually be spotted because somewhere on the wrong part of the image you will find the sharp spot where you never intended it to be.

[Daniel Browning]

sharpness is lousy...So far I only have checked the lens on my trusty 20d bodys using AF.

Suggested reading: "This lens is soft" and other myths.

[Derek Reese]

Interesting link.