Hello, I'm new on this forum.
I recently bought a used EF 70-200 f/2.8 L IS II USM from a store online thinking it would be the greatest lens I have ever owned from reading up on it a lot beforehand.
The lens looks like new and I intended to use it on a Canon R6 mk 1 with the original standard Canon adapter. But to my disappointment just around 30-40% (if I'm being nice to the lens) of the shots are in focus on the eye using Servo AF, face + eye-tracking, back button focus and using shutter speeds around 1000-2000th. I have tested this on my 5 year old daughter and my wife who have been walking, running and just doing normal things in the every day life and with this low amount of shots in focus in pretty disappointed.
I have tried all different cases for autofocus and to nap the eye tracking to different buttons. I do have two R6's and the results are the same on both bodies. The firmware is the latest on both bodies too.
I have a few other lenses like EF 100mm f/2, Tamron 24-70 f/2 G1, EF 100-400mm L mk 1, RF 24-240mm that I have done the same tests with. The 100mm f/2 gets more shots in focus by a great margin for example, about 75% in focus. I thought I had bought almost the best EF 70-200 f/2.7 lens out there, but shouldn't it perform better than this? Maybe I should have kept my old Sigma EX 70-200 f/2.8 without stabilization instead...
Sometimes it looks like the focus is on the eyelash, nose or mouth but sometimes the image is just soft. When shooting static objects or people been still it gets focus as I would expect it to. The problem is when tracking moving subjects. Could there be something wrong with the lens so it's unusual slow to track?
For example I had my wife walk mostly towards the camera from a distance looking both straight on and to the sides with her head and of 169 shots I got 52 in focus. When it gets focus it is fantastic, but shouldn't it get more shots in focus?
Is there still something I can try or change to get the results I know this lens can achieve or is it a case of trying to return the lens? I'm shooting my first wedding this summer and wanted to use this lens, but I don't want to feel unsecure if the lens will get the important shots in focus or not doing while under the pressure of the big day for the couple.
Thank you for your thought on this!
