100-400mm MK2 focusing issue

[beastbeef]

So this is a new 100-400 MK2 on an 80D.

My settings are:

1 point manual focus, evaluating metering, back button focus, single shooting, and AI servo.

The issue is it (with full AF setting on the lens) would focus at 400mm on a far object fine, however, when I try to focus on something close >1m (above the MFD) at 400mm right after, it will not focus the AF motor will not even move, I have to manual focus a little before it would find focus.

This happens from short to long too. Does anyone have any ideas?

[ebiggs1]

"Weird..."

Actually it's not.  It was/is working normally.

[RobertTheFat]

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@beastbeef wrote:

Yea everything works fine now after I changed some AF settings. Weird...

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Think of it as an expression of the fact that the lens doesn't focus as fast as the camera thinks it should.