Weird autofocus/sharpness issues: Any ideas?

[sk66]

That's not what I meant.. you said release priority and BBF only works with a single AF point. Where is THAT in the manual? Can't find it.

It's *not* in the manual... but just try it for yourself. When using BBF it will not respect the release priority setting after focus has been achieved w/ the BB initially (i.e. once. It *will* respect the setting for that first/initial activation). On my D810 it won't even respect it if group AF is selected.

If it did respect the release priority setting, then you couldn't use BBF for focus/recompose.
This is why they released the firmware update, so that it will respect the release priority settings; but only in AF-S with the single point option (which also defeats focus/recompose with these settings unless AF-S is set to release priority).

 

[HoppyUK]

Agreed, but I don't think DOF was the problem nor would more have helped really.

It does seem like an odd choice... if I were setting an ISO it would be a full stop setting (unless pushing max tolerance). Not sure that it matters though.

Ok, you've lost me here.
What benefit is there to BBF if you do not use AF-C? How is BBF/focus-recompose any different in AF-C vs AF-S?
IMO, the whole point of BBF is to have instant choice between AF-C (hold BB), AF-S (release BB), and Manual (don't use BB) behaviors all with one convenient button.

The biggest risk to AF error is in using AF-S on the shutter and focus-recompose... either aspect could cause a problem (double press/angular error). And neither is actually prevented by using BBF (although double press is less likely).

Ah, so full manual w/ MF then?

Of course I agree. When time permits there is no excuse for mistakes... but I still make them sometimes.

I don't think I've been saying anything contentious here, just good practise.

 

[Pookeyhead]

It's *not* in the manual... but just try it for yourself.

I'll take your word for it. I don't use the rear AF On button.