RE: [Leica] Tri-Elmar and Depth of Field Hyperfocal distance

["B. D. Colen" <bdcolen@earthlink.net>]

> -----Original Message-----
> From: owner-leica-users@mejac.palo-alto.ca.us
> [mailto:owner-leica-users@mejac.palo-alto.ca.us]On Behalf Of Mark
> Rabiner
> Sent: Tuesday, June 15, 1999 3:58 AM
> To: leica-users@mejac.palo-alto.ca.us
> Subject: Re: [Leica] Tri-Elmar and Depth of Field Hyperfocal distance
>
>
> "R. Saylor" wrote:
> >
> > > This I understand. My question therefore seems to be how does one
> > > calculate or even estimate just what that "as much infront of
> 'infinity'
> > > as possible" might really be?
> >
> > At hyperfocal, the far distance is infinity, the near distance is one-
> > half hyperfocal. (This gives maximum DOF.)
> >
> > If you set focus at infinity, the near distance is hyperfocal, the far
> > distance is... who knows? The mathematics gives a negative number
> > (the negative of hyperfocal, to be exact), which indicates something
> > beyond infinity.
> >
> > It has been suggested (by a Minox user, but I've lost the URL) that
> > for distant scenes, it is better to focus at infinity rather than
> > hyperfocal. The argument in favor of this involves perspective
> > geometry, which is as much off-topic as Rolex, Mont Blanc, and
> > Rolls Royce.
> >
> > Richard S.
>
> I've never thought I understood the Hyperfocal distance concept fully.
> With a 35mm lens if I stick the infinity at the right at f16 I get
> everything from 4' to infinity in focus and I am focused at 8'. I notice
> 4' is half of 8' as you say. You are saying 8' is the Hyperfocal
> distance. And I guess it is only the Hyperfocal distance at f16.
> With a 35mm lens if I stick the infinity at the right at F11 I get
> everything from 6' to infinity in focus and I am focused at 12.' So the
> Hyperfocal distance changes with each F stop am I right? I keep hearing
> about how each lens has it's Hyperfocal distance which confuses me as it
> would change with each F stop. Unless I have it wrong. Which would mean
> I am hopelessly ensnared in a circle of confusion!
> Mark Rabiner
Mark - As the ultimate "f--k the manual, just do it" guy, let me suggest
that you step out of the circle of confusion, set infinity on the right hand
f stop marking corresponding to the f stop you're using on what ever lens
you're shooting with, look to the left hand f stop marking, and shoot....I'm
sure there's some terrific technical explanation, but....
>