Automatic "best focus average" solution for selecting focus point? (was RE: filmscanners: VueScan 7.2.11 Available)

["Stuart Nixon" <sns@ermapper.com>]

> I understand what you (and others) are asking for.  I'd probably
> implement this if someone could show (with actual scans)
> that specifying a focus point manually works better than what
> VueScan 7.2.11 already implements.

Just a thought (not sure how practical this is):

Would it be possible to add an automatic "multi-point" focus option,
which would internally manually take focus at say 9 points across the image,
then select the best average that represents the happy medium of all these
points (perhaps also rejecting points for areas of low contrast), then using
that average as the focus value.

This way, there would not be much to add to the GUI - just a tick box option
(showing the divergence range value might be nice, too).

Given I am scanning 1000's of negatives, I don't really have the time
to manually select the best focus for each negative.  I would be happy to
let the scan process take a little longer if it could do something like
the above.

Regards,

Stuart

p.s. While on my soapbox here, a quick note of thanks to Ed for VueScan -
it saved my bacon with the Nikon 4000ED, given NikonScans's appalling
stability.