70-200 f/2.8L II + 5DSR AF consistency problem

[docusync]

Folks, need an advice...

My 70-200 isn't focusing consistently @ 200mm (I mostly shoot at this focal length, don't care much about the wide end). Tried several times to AFMA with FoCal - the software returns "poor fit" because the results are so inconsistent. No problems shooting and calibrating a bunch of my other lenses. What should I do?

Thanks!

[jrhoffman75]

Do you have a second body to try lens on?

Lens may need to be sent to Canon for check/repair. 

[docusync]

@jrhoffman75

I do. It was too late and I forgot to mention it in the original post 🙂 The same lens works very consistently (99%+ fit) on my 1dx2. Also, that's the only lens that's inconsistent of the 5dsr. Paradox... I was wondering if someone else had a similar problem, maybe with a different lens. Should I send both the camera and the lens to Canon?

@Waddizzle

I really like the lens, but on the 5dsr it's just acting funky...

[kvbarkley]

Call Canon, they might have a software update for the lens for the 5dsr.

[docusync]

I checked all Canon product advisories and found nothing on the lens. The camera firmware update is only for the new wifi card. Probably it's a good time to give them a call... 🙂

[kvbarkley]

Not software for the *camera*, software for the *lens* this is more common with third party lenses, but I suppose it could happen to Canon, too.

[jrhoffman75]

Are you using single point or multipoint focus?

I have read some traffic on the web about focusing difficulties with high megapixel cameras.

[docusync]

@jrhoffman75

Single point (regular, not the pin-point) per FoCal recommendation. Theoretically 50Mpx resolution is about the same if we take a 20Mpx APS-C sensor and expand it to FF? As far as I understand it's slighlty more demanding to the shutter speed and technique, but the AF is provided by a separate PDAF sensor anyway, so as long as it's accurate and the light distance to PDAF is the same as to the sensor, it shouldn't be much difference in the AF performance?

@ebiggs1

LOL - I hope they won't, and I hope they won't ask to send both cameras and the lens - I'll be left with no cameras 🙂  Emailed to the CPS support, waiting for a response...

Thank you guys for your replies! I'll keep you all updated with Canon's response.

[TCampbell]

One of my tests for a lens focus performance (using a commercial focus target) is to put the camera on a tripod, point it at the target, manually run the focus all the way "in" and make the camera focus and shoot... over and over... about a half-dozen times (or more).  Then.... do the same thing except run the focus "out" and make the camera focus and shoot.

The idea is to find out if the direction of movement makes a difference.  If it does make a difference, the lens may have excessive backlash in the focus gears and likely needs service.

[docusync]

Forgot to post an update. I had to send the lens along with my 5dsr. CPS have repaired the lens. They said it was faulty because I probably unmounted the lens while the camera was on. Not sure if that's the case, since I remember the lens was finicky from the day one. Anyway the repair was cheap and quick, good experience. No doesn't require any AFMA anymore.