John;

What I find interesting about this, is you are the one person we know on the forums that has investigated and researched how the AF system works to the extreme. You have written several nice tutorials on how to set your adjustments. Yet the irony of it all, Canon chooses you to send a 1D X with a faulty AFMA system.

Just a curious question when looking at your video. Does it only do this when you power down and power back up with the on/off switch? Or does it do it as well when the camera hibernates and comes back live?

Also did I understand this correctly, even though it doesn’t recognize the lens, if you take pictures the EXIF data shows the settings were there? If so to me that would imply that the camera does recognize the lens, but it isn’t displaying it correctly. Of course if this scenario is true, there is no fix or work around you would have to do each time you mount the lens, you would only need to do your work around when entering settings.

Rick