Re: [Leica] G2 manual focus and DOF!

["Mark_E_Davison" <Mark_E_Davison@email.msn.com>]

The manual focus facility on the G2 is very useful for scale focussing,
either when you are working with a DOF table (god-forbid) to do landscape
photographs, or for presetting a distance for quick street photography. By
depressing the focus lock button on the back of the camera as you turn the
manual focus wheel on the front,  a read-out of the focus distance appears
in the viewfinder. A common application for distant landscapes or aerial
photography is to preset the distance to infinity, as it is sometimes hard
to get the AF to focus on infinity (the G2 has one horizontal AF sensor, and
it's painful to get it focus on the horizon or wispy clouds.)

Using G2 manual focus with the electronic focus confirmation is a little
more tricky. The camera manual does not explain exactly how the focus
confirmation works. My experiments indicate that focus is confirmed whenever
the distance set with the wheel is inside the DOF interval of the target
point, using the DOF table for the widest aperture of the selected lens.
(The G2 knows which lens you have mounted, but not which aperture is
selected.)  For serious photography this is not what you want: you want to
set the focus at a precise point (for example on a particular blossom or
part of person's face) so that you know how the DOF will extend in front of
and behind.

So what I do is find the distance to the desired focus point using the SAF
autofocus mode, and then transfer the distance to manual focussing via scale
focussing.

Sometime I would love to hear a Contax engineer explain the intended use of
the G2's manual focus with electronic focus confirmation. I would trade it
in a heart beat for a real focus lock (which would remember the current
autofocus setting and park the lens there.) Or better yet, give us a G3 with
a real optical rangefinder and lenses with DOF scales.

Mark Davison
Seattle WA




- ----- Original Message -----
From: "john" <bosjohn@mediaone.net>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Friday, February 09, 2001 5:47 PM
Subject: Re: [Leica] G2 manual focus


> Guy Bennett wrote:
> >
> > >Never be surprised by fabulous photos produced by a G2 - It has only
> > >three real drawbacks - the fastest lenses available for it are f2;
> > >despite what Kyocer calls it, it does NOT have real manual focus; it
has
> > >a limited number of lenses available. But the lenses it does have are
> > >terrific, and it has some great features...
> > >
> > >B. D.
> >
> > Isn't the G2 manual focus the same as that of the old Contax
rangefinders?
> > It is mounted on the front of the body, not on the lens, as it was with
the
> > IIIa/IIIb of yore. If it is different, does anyone know how?
> >
> > Guy
> though the wheel for manual focus is in the same place a s the contax 2,s
and
> 3s etc. that is where the similarity ends.  The Contax G2 focusing wheel
does
> not move the lens it does manually what the autofocus does.  It
electronicly
> determins the correct in focus position for the lens in relation to the
film
> and when the shutter is pushed the lens moves out to the correct point.
So
> even though you can set the focus distance manualy the camera still moves
the
> lens electronically and you still have the same lag in the release.  About
the
> only use the so called manual focus on the Contax G2 is when the auto
focus
> fails to work.  A great boon but I cannot imagine anyone wanting to shoot
with
> the Contax in the manual focus mode as prefered method of using the
camera.
> One uses the Leica for that.
> John Shick