"L" stands for lemon

versedmb wrote in post #10307915
That's really a shame. Its one of my favorite lenses.

Here's mine at f/4...

Love the shot Great storytelling!

leo_jb wrote in post #10307670
I invested in an EF 70-200 f/4 USM lens a while back primarily to take photos of my kids playing soccer. The focus of the photos I took were inconsistent - about half were sharp and half were very soft, blurry even. I thought it was me and played with the settings on the camera, higher shutter speed, etc., to no avail. I finally set the camera and lens up on a tripod and tested it. What do you know - the lens can not focus at 200mm wide open. Just goes from blurry to blurrier (is there such a word?). It gets better at shorter focal lengths and is pretty clear at 135mm. I sent it to Canon (Irvine, CA) for repair, and even though it was just out of warranty, they attempted to fix it for free. Problem is, they never did fix it, even after three tries. I am about to give up. Anyone else ever had this problem? Suggestions on how to proceed?

Photos with EXIF...or it didn't happen

Here is one I took at F/4 200mm at iso 800 with mine that I bought second hand. I dont always get non-blurry shots, but I realize that when I do, its my mistake the lens is doing its part

HTTP response: NOT FOUND | MIME changed to 'image/gif' | Redirected to error image by FLICKR

come back

versedmb wrote in post #10307915
That's really a shame. Its one of my favorite lenses.

Here's mine at f/4...

AWESOME shot!!!!!

Definitely strange. The AF on mine is crazy fast, perfect for sports. Yes, sometimes it gets confused, but all lenses will at some time.

mmahoney wrote in post #10308326
After 3 trips to Canon repair with a VERY highly regarded lens I would start to consider what else in the image making chain could be causing problems .. test the lens on another body to be sure it's not a fault with the cameras AF system, also shooting sports is not as easy as the Nikon ads on TV suggest .. so post a few sample shots here with full EXIF as a start.

Yes sports can be tough, but he said he tested it on a tripod and the results where bad also. But you could have a point about the body.

Do you have other lens and do they AF ok ?

leo_jb wrote in post #10307670
What do you know - the lens can not focus at 200mm wide open.

Anyone else ever had this problem? Suggestions on how to proceed?

Mine has the same issue. It back focuses about 12" at 40', carefully measured and re-measured. My brand new EF400 f5.6 front fosed about 6" at 40'. These are both on an XT body.

I spent about 70 minutes with Canon tech peeps about these issues on two different occasions and the story at the end of all this was "send it to Canon Irvine". The problem is they will calibrate the two lenses to that specific body, and will charge you significantly for it. The lenses may or may not be perfectly right for another body after that. It all sounded like a crap shoot anyway as I'd read of people getting their stuff back from Canon and it still not being right.

Looking into it some more, I discovered this is a common issue with longer lenses, wide open, and that there is a calibration fix one can do with a small hex wrench. I did this and now the 400 focuses perfectly while the 70-200 still back focuses a bit at f4.

Canon themselves clearly have acknowledged the issue by now incorporating "micro focus adjust" on the 50D, 7D, and 1 series cameras.

lankforddl wrote in post #10307694
I suspect that your experience with the 70-200 is 1-in-a-million. This lens and the lot of canon 70-200 are the best team of lenses that exist on earth.

Slow down Seabisquit! Evangelism isn't what's required here.

Nifkin wrote in post #10308487
I wouldn't go too far (this time in the other direction)

So you sent this lens back to Canon not once, nor twice, but three - count 'em - three times, and it still doesn't work?

Hmmmmmmmmmmmmmmm. I think something else is afoot....

Wouldnt Canon have told him the third time he sent it in that the lens was fine rather than attempting to fix it? I dont think anyone in the canon workplace likes just having busywork for no purpose?

But this lens is generally accpeted as a great lens. I hope it gets all worked out in the end.

Im going to chalk this one up to user error...until more evidence is provided. I mean whats the point of starting this thread without complete evidence to support this nonsensical rant and then just dissappear??

LOL. Ya the title is showing a little bit of emotional bad judgement.

Brain Mechanic wrote in post #10309774
Im going to chalk this one up to user error...until more evidence is provided. I mean whats the point of starting this thread without complete evidence to support this nonsensical rant and then just dissappear??

How can you chalk it up to that. I'm thinking he bought a used lens that had problems. I can't figure why other people started posting images with their lens.

corndog cabernet wrote in post #10309587
I discovered this is a common issue with longer lenses, wide open, and that there is a calibration fix one can do with a small hex wrench.

Is this hex wrench self-calibrating procedure for the body or lens?

I recall seeing online instructions on body calibration which involves a (modified) wrench but have never seen anything about do-it- yourself lens calibration .. I'm sure both are simple procedures once you know what to do and have the tools.

Still, I've seen the guts of a modern lens and can tell you there are a whole lotta wires in there .. not for the faint hearted.

Brain Mechanic wrote in post #10309774
Im going to chalk this one up to user error...until more evidence is provided. I mean whats the point of starting this thread without complete evidence to support this nonsensical rant and then just dissappear??

Can you say troll?

Take Care,
Cheers, Patrick

Leo,,is the 70-200mm your first tele zoom??

Long lenses are a whole new experience in shooting than say a wide angle to short zoom.. More care is needed especially at the long end and you have to keep your shutterspeed up.. You'll find that most poor quality images are due to user error and not the lens/camera.. The Canon 70-200mm zooms are outstanding lenses,,second to none..

Post a couple of bloopers..