I don't think the camera knows the minimum focus distance on any lens
that doesn't have that data on it's chip. So it's only available for
some F series lenses and later. It might also be available from the A
lenses supplied with the MZ/ZX-M I think there were two lenses that were
pretty much the same as their FA counterparts, a 35-80 and a 80-200mm,
which might be pretty rare as the FA versions were pretty inexpensive to
begin with.
I really don't think that the autofocus system is smart enough nor are
the lenses standardized enough for the system to interpolate anything
about focus throw.
The AF system misses the focus point and simply tries again, running
through the entire range of the lens. If after a certain amount of
effort, which seems to be random, but probably isn't, it simply gives
up. The K-5II gives up a lot less often, and gets the right focus more
often, than earlier cameras but it still gives up eventually.
On 7/17/2016 12:46 PM, Jos from Holland wrote:
The metadata also shows the minimum focus distance. How can the camera
know, even when it does not know which lens is mounted?
Only the lens can tell the minimum focus distance.
But if the camera knows the minimum and maximum focus distance, than
it could estimate the focus distance!
Is that why it hunts now and than: to throw the AF between minimum and
maximum focus distance and interpolate values in between?:-)
Greetz, Jos
On 17-Jul-16 18:11, Larry Colen wrote:
Jos from Holland wrote:
Going through the metadata of K5 and K1 files I observed that the
hyper-focal distance is available, based on the applied aperture and
focal length.
Wouldn't it be nice if this info was visible on camera for manual
adjustment, or even better an select-able auto focus mode with
hyper-focal priority?
I wish the lens mounts would return focus distance to the camera body.
If they can engrave it on the lens, then they can know it
electronically.
Also the circle of confusion is given: 0.02mm for K5 and 0.03mm for K1.
Considering the a full frame camera will / can be used for larger
prints, I would prefer to keep the circle at 0.02mm for K1 as well. Or
better: user selection of he circle size resulting in corresponding
hyper focal distance.
Greetz, Jos
--
I don't want to achieve immortality through my work; I want to achieve
immortality through not dying.
-- Woody Allen
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