D780 AF Fine -Tune at Wide AND Tele Focal Lengths

AF Fine-Tuning Options

So a 2 point system allows a zoom to have a wide and tele AF control point... or I suppose a mid and long if that's where you want it?

It seems to have an AF fine tune menu for Viewfinder shooting AND LV shooting too?

You gotta wonder whether this could be a firmware upgrade for the more recent DSLRs??

Ooh, that's exciting. I mean, it wouldn't help for a lens like the 80-200 which seems to change telecentricity during focus as well as zooming, and it may be less accurate than the Sigma 4x4 (I think) system, and it would be nice if multiple focus points could be tuned... but it's a step in the right direction.

Do you need tuning for PDoS? I knew it could miss, but I don't think I realised the geometry came into it - unless they're worried about chromatic aberration throwing the AF point.

I'll have to read a manual...

it wouldn't help for a lens like the 80-200 which seems to change telecentricity

Is that what happens when a zoom lens's front element group changes direction while zooming? I.e., those lenses where the shortest excursion of the front group happens somewhere in the middle of their zoom range rather than either extreme? I always have trouble with these lenses in terms of focus, as they require at least three different AFFT settings depending on focal length.