85 L II - Focus problem

Hi everyone
This is my second prime lens and i think the focus lock of my copy is not accurate.
for some test shots, I fixed the camera on a tripod and the subject on the wall, level and parallel to the camera.
Selecting central point spot focus on 5D mark III and taking many shots i found that the lens focuses in a range of back to front and every time i press the shutter button the focus distance differs. the difference in focus distance is clearly visible through distance window on the lens.

Content warning: NOT AN IMAGE

I don't get what your doing? From what I can tell, your taking a picture of your 85mm f/1.2L II and its not coming out clear? What lens are you using to take the picture? It looks like its not in focus? Do you have another picture from further away so we can see what is in focus? It also looks like you zoomed the picture beyond 100%?

Take Care,
Cheers, Patrick

Saint728 wrote in post #15509691
I don't get what your doing? From what I can tell, your taking a picture of your 85mm f/1.2L II and its not coming out clear? What lens are you using to take the picture? It looks like its not in focus? Do you have another picture from further away so we can see what is in focus? It also looks like you zoomed the picture beyond 100%?

Take Care,
Cheers, Patrick

No look at the distance meter position.. he's taking a photo of the lens after it's decided on what to lock focus on.

What is on the wall? a test chart? If it's just plain wall with no contrast, that would be normal.

Thanks for replies.
the subject on the wall is a printed focus chart with enough contrast and there is no problem with the other lenses when i do the same.
I'm using 5D III and 85L II and i found that most of my shots are useless so i decided to test the focus accuracy and micro adjusting if needed, but i found that the focus is terrible. (some times back focused and some times front focused. just about 45% of shots are normal)
I think it shouldn't be normal for such a lens and any opinion or experience can help me to decide whether to send my lens to canon service center or not.
the picture i posted above shows the changing in focus distance calculated by the lens while the real distance between lens and subject has never changed during shots.
Thank you