Posted by Henry on April 15, 2001 at 12:18:09:
In Reply to: Re: 203 Raptar on a Century posted by Mal Stone on April 15, 2001 at 11:17:55:: Dear Henry,
: Thank you for your reply.
: I've checked my Raptar and it focuses at infinity at about 5.5 inches from centre of lens to film plane. I've checked the rangefinder arm in the camera box and you're right - it is disengaged as I close focus, so it can't be callibrated for the lens. My infinity stops need adjusting on infinity for the Raptar and I also have two focus scales - one on each side of the focusing bed. Don't know how to callibrate these with the lens I have. I think that one appears to relate to the 103 Graftar but can't fathom out the other one which scales 4 ft. to infinity on a scale of one and an eigth inches.
Mal,
I really wish I could see your camera, as it sounds from your
description that it differs a bit from my Century, especially in
the matter of the focusing scales---you say there is one on each
side of the bed, whereas my camera has them only on one side. So if
the following remarks don't make any sense, I beg your pardon.
ANYHOW..... If your 203mm Raptar focuses on infinity at 5.5", then
it must be a "true" telephoto, i.e., one whose focal length is
shorter than the theoretical for a 203, which is 8" (actually
7.992" by my calculator, which is 203/25.4)---that's where my 203
Optar is tack sharp at infinity, but fully extended as I mentioned.
If you want to move your infinity stops it's a simple procedure:
loosen the tiny little screws with a jeweler's screwdriver, focus
on infinity (I've heard that some people use the full moon, but
probably your friendly neighborhood smoke stack or water tank will
do as well), slide the stops up against the base of the front
standard, and tighten the screws. Assuming you have the folding
stops, you can place them either in front of or behind the base;
you might prefer the latter if there will be interference with the
inner focusing scale, which slides in the same track as the stop on
the left side (looking from behind). It sounds to me as if the 1
1/8"-long scale on your camera MIGHT work with the 203; this is an
assumption I'm deriving from the observation that the focusing
scale for my 101mm Optar is 15/16" long between the 4 ft. and
infinity markings---but I'm not really sure, as I have no
experience with a focusing scale for the 203. Anyhow, once you have
tightened down your infinity stops, and without moving the focusing
knobs/yoke, loosen the two screws on the inner scale (that's the
one with the little arrow and the 50-100-infinity marks) and line
up the infinity marks on the inner and outer(fixed) scales. Now get
out your long tape measure and locate objects that are 50 and 100
feet from the camera. If you've lived a good clean life, the 50 and
100 marks on both scales will line up precisely when the respective
objects are in focus. If not---you need the part that Alec
mentioned! Life is so d--n complicated! (Are you metric across the
pond? If so, sorry about the feet and inches.)
Henry