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 ("http://www.lensrentals.com/news/2008.12.22/this-lens-is-soft-and-other-myths).

[Derek Reese]

Interesting link.

[Colin]

Boy, that sure does describe me....


How much does it cost to belong to Canon Professional services?


I sent back my 50mm f/1.2L becaues of backfocusing, though I don't know if that can be helped because it focused fine at f/1.2, it just sucked up close when stopped down from f/2.0-f/4.0. I sent it back with my 5D, and they were supposedly going to look at them together...


Do they calibrate them at different apertures as well? They claimed to have made an adjustment to a PC board, but I don't know. I do know it came back with the same behavior.


However, I also just returned a 135mm f/2.0 for an exchange. It had the same problem with two bodies (5D and 30D), both of which worked fine with all of the rest of my lenses.


I told Canon, and they didn't explain the whole tolerances and calibration thing. They said that the pictures looked fine, and that if I wanted more in focus, I should stop down. In each of the pictures, I used the center autofocus point, and focused on the TIP of the screw. I told them that the only one which was REALLY right was at the minimum focusing distance, and then as I moved farther away, it got worse and worse.


These are crops that I sent them. You tell me if I'm the jackass.... [:)] After reading this, if it wasn't for the money thing, I'd be inclined to order a 1DmkIII and a 5DmkII right now! If it's in focus, the performance wide open is phenomenal.








http://i110.photobucket.com/albums/n87/boujiluge/ScrewedFocus0001100Crop.jpg


http://i110.photobucket.com/albums/n87/boujiluge/ScrewedFocus0002100Crop.jpg


http://i110.photobucket.com/albums/n87/boujiluge/ScrewedFocus0003100Crop.jpg


http://i110.photobucket.com/albums/n87/boujiluge/ScrewedFocus0004100Crop.jpg


http://i110.photobucket.com/albums/n87/boujiluge/ScrewedFocus0005100Crop.jpg

[peety3]

How much does it cost to belong to Canon Professional services?


I sent back my 50mm f/1.2L becaues of backfocusing, though I don't know if that can be helped because it focused fine at f/1.2, it just sucked up close when stopped down from f/2.0-f/4.0. I sent it back with my 5D, and they were supposedly going to look at them together...


Do they calibrate them at different apertures as well? They claimed to have made an adjustment to a PC board, but I don't know. I do know it came back with the same behavior.





CPS got updated not too long ago, such that you have to make a majority of your income from photography.


I've heard that the 50L has focus shift issues when stopped down between f/1.2 and f/5.6. That's probably what you're suffering from. See http://www.lensrentals.com/rent/canon-50mm-f1.2-l/for-canon for their description.

[Colin]

I wonder how they verify the majority of your income....


I'm incorporated. Photography is part of my business. My corporation gives me a paycheck. It'd be nice to generate the majority of my income with photography. I'd prefer it over programming control systems.


Maybe I'll ask them...


Otherwise, I can just send lenses back until they match my bodies, which seem to at least match each other...

[Colin]

I've heard that the 50L has focus shift issues when stopped down between f/1.2 and f/5.6. That's probably what you're suffering from. See http://www.lensrentals.com/rent/canon-50mm-f1.2-l/for-canon for their description.
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Yeah, that article/summary pretty much sums it up. I loved it. I hated it. I sold it. I miss it. I never want another one.


Make a Mk II version that can focus correctly at all apertures, and I'll be all over it. I want the 85mm f/1.2L IIwithout manual focus by wire, closer minimum focusing distance, weather sealing, and at 50mm. I loved what I got when I got what I wanted, but I want to be able to depend on at least a single focus point to be in focus! It made me want to beat somebody with a frozen tuna! I'd like to meet the guy who decided that behavior was okay, shake his hand, and then pull his arm out of his socket.

[peety3]

I hear you. Well, I want the 85LII first though, but I'll take the 50LII too when the funds are there. ;)

[Scott]

Focal length, I had a similar issue with my lens, not an L but with all the advice I got it came down to basics', focal length. Yeah you can up the speed a bit but try the basics' first, distance yourself a bit from the subject and take a few shots at different focal lengths with an increase to your aperature, bump that up a bit also. The issue I had with my lens was that the tip of the nose was in focus and the eyes were out of focus. I bumped up the aperature from 2.8 to 5.6 - 8 and put a few extra feet between me and what I was shooting and that fixed the problem. Then slowly adjust focal length, aperature and shot again, compare, trial and error. I'm only new to this myself but I have found going back to basics' fixes a lot of my issues, hope this is helpfull to you.