Re: [Leica] DOF and focusing

["Raimo Korhonen" <raimo.korhonen@pp2.inet.fi>]

Its faster still if you divide the range you want to be sharp into thir=
ds
and focus on something at the end of the first 1/3. I have found that i=
n
daylight this works very well without consulting the DOF scale.
Raimo
photos at http://personal.inet.fi/private/raimo.korhonen
my=F6s suomeksi
- ----------
> From: Jim Brick <jim@brick.org>
> To: leica-users@mejac.palo-alto.ca.us
> Subject: [Leica] DOF and focusing
> Date: 28. syyskuuta 1998 4:20
>=20
> Just a note about my trip slides.
>=20
> I've gotten through a bout 20 rolls. As I said earlier, I used the 35=
/1.4
> ASPH most of the time. Some of the stuff could be considered happy sn=
aps
as
> it involved the three ladies. Since I was using my M6 exclusively for=
 the
> last 7/8's of the trip, and since much of the stuff was not happy sna=
ps,
I
> devised a focus method that seems to have worked perfectly. What I se=
e on
> the slides confirms this. And I'm using a 6x Schneider ASPH lupe.
>=20
> My entire past has been using a ground glass and checking DOF visuall=
y
> while stopping down. This rangefinder stuff was difficult for me. So =
I
> started using the engraved DOF scales on the lens. I would focus on t=
he
> nearest object that I wanted to be in focus, and I took a meter readi=
ng
and
> figured out the exposure. I placed the foot/meter mark of the focused
> object one f/stop wider than the actual f/stop that I was using. If m=
y
> exposure was 1/125 at f/8 and the closest object was 8' away, I place=
d
the
> 8' mark opposite the f/5.6 mark on the DOF scale. I then looked to se=
e
> where infinity and the farther distances fell. If the infinity mark w=
as
at
> say f/5.6 I moved the infinity mark to the f/8 DOF mark thus giving m=
e a
> little more leeway in the close end. I always favored the close end.
After
> a few days, this became very very quick. By keeping the close stuff a=
t
one
> stop greater than the actual shooting aperture, crisp sharpness is
> guaranteed. This is basically hyperfocal -1 focusing, with a close en=
d
> bias. It worked because nearly all of my slides are tack sharp from f=
ront
> to back. In those situations that the DOF would not span the entire
> distance, I figured out what was important and placed that within the=
 DOF
> scale -1 zone. I sometimes would go for hours and never actually use =
the
> rangefinder.
>=20
> This is a hellova lot faster than visually checking DOF on a ground g=
lass
> screen. I'm beginning to like my M6. Now if they could somehow make
lenses
> that didn't cut off part of the viewfinder image...
>=20
> Jim