Canon EF 24-70 L fails to autofocus at 70mm.
5D MkIV body.
Not the same problem as losing focus at different focal lengths, which is well documented here.
With the lens set to AF, lens will focus at all focal lengths until I turn to the maximum magnification...fully counter-clockwise. This is on a tripod without moving the camera relative to the subject. In other words, at 24mm autofocus beeps, but going to the max it will not autofocus, even if I move the body slightly to put different objects in the path of the AF points.
If I turn the zoom ring clockwise, just slightly below 70mm, then autofocus works again. I don't remember this being normal behavior.
I cleaned the lens and camera contacts, but no improvement. In fact it does the same thing on a T3i body.
Any thoughts? I can live with it now that I know the workaround, but is it a defect?
cheers
