Hyperfocal focussing is based on the fact that sharp
focus or at least suffieciently sharp focus doesn't
happen on a single plane.
You can take advantage of that to take pictures where a
wide depth of things are in focus.
The hyper focal lines on your prime lenses and some few
zoom lenses allow you to set the focus so that this will
happen. If you look through the viewfinder when it is
set properly, some things will look out of focus.
So how is it done?
First select an aperture. Which one depends on you,
although the more stopped down the aperture is the more
depth of field you can get.
Now on a prime lens there is a scale which has some of
your available apertures listed twice. For example on a
F1.8 you would see...
f16 f8 f4 O f4 f8 f16
where the O thing is the center
Right above this list is the distance scale. The
distance scale tells you at what distance the plane of
sharp focus will be. What ever number appears above the
center mark is the distance to that plane.
Now let's say that you wish to use hyper focus and that
the most distant object is 8 feet away.
Let us also say you selected f16 for your aperture.
Now move the focus ring so that 8ft on the distance
scale lines up with the right most f16 on the aperture
list. If you look above the other f16 (towards the left
if you point the camera away from yourself.) the
distance scale here will tell you the closest distance
that will be in clear focus.
One way you can tell if you have the orientation the way
I descibed is because the infinity symbol will not go
all the way the left most aperture. In fact it will not
go past the center mark. This makes sense distance wise
because you would never need to focus past inifinity. It
also makes sense hyperfocal wise in that inifinity would
never be the closest focusing distance.
One further note. The regions of focus in front of and
behind the sharp plane of focus are not as sharp as that
plane. Sharpness will fall off the farther away some
object is from this plane. What this means is that there
are three regions to think about in the image. The plane
of best focus, the region between you and that plane,
and the region behind that plane. This is just something
to think about when you go out to practise.
I hope this was helpful.
Date: Mon, 01 Jul 2002 10:15:27 -0600
From: Sean Davis <sfdavis@xxxxxxxxxxx>
Subject: [OM] Hyperfocal focussing?
(de-lurking)
Could someone do me the favor of explaining the concept
of "hyperfocal
focussing" (don't know if i have the term right). I
have a small idea
of what it's about, but don't really get it. Does it
have anything to
do with the depth-of-field scale on a prime lens? Every
time i try to
use that, i simply end up with a small focussed part in
the middle,
and everything else out of whack. Confused!!
Sean D.
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