I purchased a brand new Canon EOS 1DX Mark III a few month ago. When I was trying to shoot time lapse using this camera with a Canon 600mm lens, I found out the the image on Liveview was constantly drifting , especially when IS was turned on. I was NOT able to focus and not able to make time lapse shooting. There was no problem if I used my old Canon 5D mark III, the image on LCD was stable.
The next day, I called Canon Tech support and worked with a technician named Phil for one hour and a half. Phil was able to reproduce this problem in his lab with different type of lenses. He created a ticket and escalated immediately. Three months have passed and there is NO answer and NO firmware update (I already updated to Canon's latest firmware and the problem still exists).
This is a major defect for me.
If anybody do not have this problem.

