85L 1.2 II inconsistent focusing

Ok..I did some test because I noticed that some of my images are not focusing correctly. When I use the middle AF point everything works well..focus is on the spot. But when I use the 1 o clock AF point (the one between the top and the right AF points) I get inconsistent focus.

I used a tripod for this test and focused on the left eye of the doll(your right when facing you)..here are the sample pix.

This is on spot..the face is in focus. @f2.8

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MF is key sometimes.

glowie wrote in post #2047281
Ok..I did some test because I noticed that some of my images are not focusing correctly. When I use the middle AF point everything works well..focus is on the spot. But when I use the 1 o clock AF point (the one between the top and the right AF points) I get inconsistent focus.

I used a tripod for this test and focused on the left eye of the doll(your right when facing you)..here are the sample pix.

This is on spot..the face is in focus. @f2.8

Hosted photo: posted by glowie in
./showthread.php?p=204​7281&i=i166650548
forum: Canon Lenses

But this one the face is out of focus and the foot becomes in focus, while the AF point is still on the right eye. @f2.5

Hosted photo: posted by glowie in
./showthread.php?p=204​7281&i=i240029663
forum: Canon Lenses

I've read that this is normal for this lens and just have to accept the fact that it does this from time to time.

Should I return it and ask for another copy? or will I just get the same results?

Thanks a whole heap!

I assume that this was taken on a 20d? I had the same problem when i first had mine, i sent it back for calibration and its been much better, do remember though that the other focus points "non centre" are not cross type focus points, as such they will not give the same degreee of consistency, i have found very similar findings when i use my 85L with other points. The fact you say yourself that when you use the centre point focus is fine and consistent shows to me the lens is not in question.
Out of curiosity why did you shoot the second test pic @2.5 not 2.8?

This thread is killing me...I didn't know there was any such prob. with the lens. Do you mind telling me where you read about the prob?

i don't think it is a problem with the lens, i think its more a problem with expectations of the 20d's non centre focus points.

Thanks for the reply guys!

Baybud -
A friend asked me to do a comparison between the 85 1.8 and the 85L. So I was shooting images at different F stops.

I see that your also using a 20D. So is this more of a 20D issue? because I also have the 35L and it's perfect on all AF points.


Permagrin -
I read about the inaccurate focusing here (8th paragraph):

http://www.the-digital-picture.com …L-II-USM-Lens-Review.aspx

here's a quote:
"The original 85 L was sharp even at f/1.2 and it got even sharper when stopped down a small amount. The new lens appears identical to me. My biggest problem with comparing the two lenses is getting both to focus identically. I returned my first two Canon EF 85mm f/1.2 L II USM Lenses in an attempt to get one that focused accurately consistently and am now using the third with similar results. At some point, I have to accept that this lens is not the accurate-focusing lens I want it to be. The lenses do not front focus or back focus consistently - but randomly seem to mix both scenarios in with right-on focus. The DOF is very shallow at f/1.2 - accurate focusing is mandatory. The ISO 12233 Chart sample crops will show the older 85 L to be sharper wide open. This is not what I am seeing in real shots, but these are the best chart samples I was able to get (including with manual focus and the 2.5x Canon Angle Finder C)."

I'm returning my 85L for a new one and see If I get the same results. I am beginning to love this lens but this issue is leaving a bitter taste in my mouth.

Thanks again!

thats hard to say, all i can say is that being a longer focal length + a larger aperture, DOF will be much smaller with the 85L, with that being the case any focus problems are going to stick out like a sore thumb. I would test the 85L with centre point at a variety of distances @1.2 and see if it still behaves, if it does i would suggest the lens is fine.
Also be mindful how autofocus works, sometimes perceived focus errors can occur because the autofocus has tracked onto a more "desirable " object just outside the box, in reality the focus points don't reflect the true size of the sensor, if you have ever tried to focus when there is a chain fence in the way you will know what i mean.

If your in doubt still, send it back to canon "i assume its under warranty?" they can easily fix the focus issues, as a matter of fact i received back my 35L today which was front focusing like a bandit lol, its now much much better, of course it's not perfect but the 20d's AF system isn't perfect, but its good.

I wouldn't advise sending the lens back if it is only the AF at fault, there is possibility that you could get an optically worse lens, its much easier to sort out the AF if you are happy.

Sorry this has all been a bit jumbled, i'm dealing with a few family issues at the moment which have left me feeling a little low and disperate, unable to form sentances lol.

Anyway hope you get it all sorted out to your satisfaction.

Thanks a lot Baybud!

I also tested the center focusing using a Focus tester print out. The results are perfect, the line where it's supposed to be sharp is spot on.

I'll keep thins baby for one more week and do some more test.

I hope your family issues get sorted out soon..life is funny that way sometimes...so keep your chin up and shoot some amazing photos!


Again thank you very much.

lol i'll try

glowie wrote in post #2048397
Permagrin -
I read about the inaccurate focusing here (8th paragraph):

http://www.the-digital-picture.com …L-II-USM-Lens-Review.aspx

Thank you for the link Glowie. That definitely gives me something to think about. Let me know if you find it to be a focus point issue that Baybud is talking about.

baybud wrote in post #2048457
Sorry this has all been a bit jumbled, i'm dealing with a few family issues at the moment which have left me feeling a little low and disperate, unable to form sentances lol.

Baybud, I do hope things work out for you.