24-70 L FINALLY fixed!!! :)

Well I have posted multiple topics about how screwed my 24-70 was in the sharpness area. I had sent in twice with no luck. Some people here were saying I was asking too much. But I disagree, I feel that the L should be sharper or as sharp as my previous Tamron. I think for the cost, I was paying for better color, and build. I assumed the sharpness would be there. Anyways, a select few kept pointing me to send it back. It was a PAIN in the @$$, but it all paid off when it came in tonight and ACTUALLY created sharp images, both wide and long.

Well I don't want to go on a rant about it, but I wanted to share the word, that these things can be super sharp, and if not, send it in! It's a pain, and it's sad they come out from the factory and service centers this way, but if you persist, your lens will be beautiful!!!

Interesting, I'd like to hear more if you're willing to discuss details...?

In particular, what were you seeing prior to each time you sent it in for service? What where the issues or problems that you felt were not being resolved to your satisfaction? Were some problems introduced as a result of service, and how many times did you actually have to go back and forth?

I'm curious not because I have any issues with my lenses but it would be good information to keep in mind should there be any problems with current or future purchases. From my understanding, the 24-70/2.8L is a fairly unusual design, and it does have some shortcomings because of it. Have you had a chance to put it through its paces and are you satisfied with how it's performing now?

no problem, I want to share.

Well, I bought the lens in April. Noticed it was soft on both 24 through 70 at 2.8. Sharpness wasn't achieved till stopped down to F8 or higher. some people told me I was asking too much. But I didn't believe it.
Well I sent it in. I received it back within one working week. The details said, they duplicated the fault, replaced electronics inside, dusted, calibrated, and cleaned. I checked it out when I received it, it showed the identical problem from before. I sent it back the second time. Received it back. Same "solution". When I tested it out, it was DEAD sharp on the long end, but the wide end was even WORSE!

So Third and final time being sent in, I sent it to the Jersey Service center. This time the "collars" were replaced.

I have yet to put it though it's paces. But doing the simple in house testing here, it is doing great. I will shoot some more tomorrow with a subject at various distances, and shooting between F4-2.8 24mm-70mm

Interesting... wait so where did you send it the first two times around? Irvine, CA?

If you weren't getting sharp results at the plane of focus @ f/2.8, you were absolutely justified in sending it in.

I have a suspicion that when the service center technicians look at the lens, they do some standard test shots to diagnose the problem but I don't think they really do much in the way of really careful post-operative testing. I bet they just replace some components and assume that fixes the problem, and do some casual tests afterward.

I think it takes a lot of time to do comprehensive test shots on a zoom; you've got to choose multiple focal lengths and apertures, and then evaluate each shot.

Keeps us informed on how your testing goes! I'd like to see what you discover.

First two times were Irvine CA as you said. I also agree the techs do not have a suitable test setup. I was told (during one of the calls I made) that the techs used 1Ds to test the lens. I don't know exactly what that means, but it doesn't sound like a very thorough way of testing. Maybe similar to what you were saying.

I will post some results along with my final conclusion. I do hope for my sake and Canon's that this lens is fully repaired.

I've lost hope. Canon has received 24-70's from me on about 7 occasions and none of them came back proper on the wide end. All 'within spec', but grossly misfocusing on the wide end, tack sharp and accurate on the long end.

Glad you got yours figured out. I've given up and use the 17-55 instead... which is an AF miracle performer.

They are referring to the type of camera body they mount the lens to in order to test it. So we know they are using 1D-series cameras, either the 1D or 1Ds. What we don't know is if they are using Mark I, II, or III versions of those bodies.

In my opinion, they need to use either the 1Ds Mark III or 5D Mark II for EF lenses, or the 50D if it is an EF-S lens. They need to use the highest pixel density sensor available for that type of lens, in order to determine whether the test shot is sharp enough, otherwise the limitation could be the sensor's Nyquist frequency instead of the lens's resolving power.

Did you take notice on the CA (chromatic aberration) I got mines back and noticed it is somewhat excessive. Anything in focus is fairly ok, but fore and aft suffers from heavy CA. Just curious if I should send it back and file warranty. Thank you.

bobster1 wrote in post #8496946
Did you take notice on the CA (chromatic aberration) I got mines back and noticed it is somewhat excessive. Anything in focus is fairly ok, but fore and aft suffers from heavy CA. Just curious if I should send it back and file warranty. Thank you.

This is a commonly reported problem in the 24-70/2.8L, in which OOF subjects exhibit heavy red/cyan color shift. I think this is actually an intrinsic property of the design of the lens.

I had CA before...But nothing I was too concerned about. Tomorrow, I will try to post some test shots (wide and tele) and hopefully we can see (or not) if there is Ca to follow.

You can't post this thread and not provide a sample pic!

BEEEsH wrote in post #8497195
You can't post this thread and not provide a sample pic!

GOSH! give me a few...hours

Livinthalife wrote in post #8498235
GOSH! give me a few...hours

It's been 4 hours now omgosh

Here's a quick sample for you all who are interested.
Full pic

Shot settings plz kthx