Some zooms do have swooping lines. Just set infinity opposite your
f/Stop line.
DoF is always arbitrary - it depends on your standards & how much
you will want to enlarge it. But watch out, smaller apertures lead to
less resolution (diffraction-limited).
Theoretically, the best resolution is at the widest apertures.
Practically, there's a happy medium which varies with the lens.
There's a hyperfocal calculator at
http://www.outsight.com/hyperfocal.html
The hyperfocal distance is arithmetic by f/stop and geometric by focal
length. The hyperfocal distance at f/5.6 is twice the distance for f/11.
At a given aperture, the hyperfocal distance will be 4x the hyperfocal
distance of a lens of half the focal length. So you could look at the
DoF scale on another lens & recalculate fairly easily.
Tom
On Thursday, November 29, 2001 at 12:48, John Hudson
<olympus@xxxxxxxxxxxxxxx>
wrote re "Re: [OM] hyper focal scales, or lack there of" saying:
> Clendon Gibson wrote:
> >
> > I have noticed that most of my zooms lack a hyperfocal
> > scale on the barrel (or anywhere else that I know of).
> >
> > I figured I would ask the wise and beneficent members
> > of the list for work arounds.
> >
> > In other words, if you wanted to do a landscape with
> > infinty at the far end and 8 (or whatever the lens can
> > do) for the near end at f16, how would you manage
> > without the scale?
> >
> > Thanks!
>
> For any given focal length a particular aperture will give a specific
> range in front of and behind the subject which will be in focus. Alter
> the focal length but hold the aperture constant and the front to back
> distance of that range will also change. Alter the focal length and
> alter the aperture and the depth of that range will change again.
>
> It seems to me obvious why a zoom lens does not have a
hyperfocal scale
> on the barrel; there are two variables at play, namely focal length
and
> aperture both of which impact upon the depth of field.
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