Kalart RF Adjustment Question
jon wells
with 135mm lens is 3.5 feet. This creates a parallax problem at this
distance. According to the manual, you compensate by lining up the RF
window and lens in a particular manner. While outlined, the
instructions are unclear to me. I'm looking for some clarification as
to exactly what I'm supposed to do. The instructions are shown in a box
at the bottom of page 8 of an on-line manual at
http://www.graflex.org/speed-graphic/kalart-manual.html .
The three vertical distances are difficult to make out, but appear to be
from left to right
6 3/4", 6", and 5 1/8". A text-only version discusses this issue in the
last three paragraphs of
http://www.graflex.org/speed-graphic/kalart-adjustment.html .
Any held is very much appreciated.
Richard Knoppow
The Kalart is set up at infinity, 15 feet and 4 feet.
Some care is needed since if the infinity setting of the lens is not
correct the rangefinder will be impossible to adjust.
The preliminary settings for the two internal sliders are:
Lens FL 15ft 4ft
127mm 13 3.0
135mm 15 3.5
152mm 17 5.0
162mm 17 6.0
165mm 19 6.0
Note that this is for 4x5 cameras only.
To set up the RF first check the position of the actuating lever on
the RF shaft. It should just touch the back of the camera case when
the RF is at its mechanical stop. Earlier RFs have a flat section on
the end of the shaft. Make a wrench for this out of a small strip of
metal with a slot filed in it. This can be used to set the RF shaft to
its stop. Tighten the set screws for the actuating lever with the
lever against the back of the camera box.
Later RFs have a threaded hole in front of the body, near the front
sllider, for the infinity adjustment. A long screw can be threaded
into this hole to force the RF to its infinity position. It can also
be actuated by sticking a jewelers screw driver or the smooth end of a
small drill into the hole. Adjust the RF arm as above.
Next, check the infinity setting of the lens.
The focus track should be racked out about 1/16 to 1/8th inch from its
back stop. Set the lens eccentric infinity corrector on the front
standard for its centeral position (slot vertical).
Lock the focus track and slide the lens until its focused sharply on
an object at infinity. For accurate adjustment the object should be a
quarter mile or more away.
Lock the infinity stops to fix the lens in this position on the
focusing track. Use a small square to make sure the lens is exactly
parallel to the back.
The RF should indicate infinity close to this position if everything
is set up right. Small errors should be corrected using the eccentric
adjustment on the front standard. There is an auxilliary (and
undocumented) infinity adjustment screw below the bottom prism. It can
be adjusted if the infinity position set up as above appears to be far
off the mark. Before using this adjusment it is better to reset the
position of the standard on the focusing track. Check where the RF
indicates infinity. It should be within the rack out limits given
above (1/16th to 1/8th inch). If not, use the prism adjustment to get
in on. There is some backlash in this adjustment. Tap the RF after
making it to make sure everythingn settles down before proceding with
the rest of the procedure.
As part of the infinity setting procedure set the lateral
coincidence. This is done with a screw on the front of the RF just
below the upper window. Set it at infinity. The screw is mounted on
the casing. It has a slot in its end which engages the adjustment tab
on the top mirror. Set it with the case on, then take the case off for
the rest of the procedure.
After setting up for infinity set the 15foot distance. This is the
rear slider. it may take several adjustments alternating between the
infinity corrector and the rear slider to get both right.
After getting them on set up at four feet.
Make a target with two crosses on it. One at the lens postion and
another at the position of the top window of the RF. Set the camera up
exactly parallel to this target with the centers lined up. Set the
front slider.
Then re-check the 15 foot and infinity position. Infinity will have
changed little, if at all, but the 15 foot adjustment may need to be
touched up. If so, re-check infinity, these two interact a lot.
Then recheck 4 feet, it will probably have to be changed. Again
juggle between infinity 15feet and 4feet. If the camera has never been
set up you will have to do this several times before everything falls
into place. Eventually, when you get it set, the RF will very _very_
accurate over the range from infinity to about 3.5 feet, the near
limit depending on the FL of the lens.
Use a good loupe to check the ground glass focus for each
adjustment.
NOTE--CAUTION-- The lock screw for the 15 foot adjustment (at the side
of the RF) has BACKWARD THREADS. Be very careful not to force it. Its
very easy to forget and break the head off the thing. It LOOSENS GOING
CLOCK WISE.
What else? Clean the surfaces of the partially silvered mirror at
the top with pure isopropyl alcohol and very carefully, the silvering
comes off.
If you have a dim mirror due to some of the silvering coming off put
a bit of neutral density filter over the inside of the top window,
that will incrase the contrast of the two images.
According to a letter on the Graflex site suitable mirror material
is available from Edmund Scientific.
A further note. It will be necessary at times to put the case back
on the RF to do the adjustments. This is for two reasons. First, to
locate the eye properly, second to keep out stray light. The eye must
be in the right postion of the adjustments will be in error.
Its not necessary to fasten the case on the RF but it shoule be
removed and replaced very carefully.
The only other advise is to be very gentle with things, small screws
are easy to damage.
Once set up the RF will be very stable and very accurate.
If you take the RF completely off the camera you can take the base
plate off and clean and relube the cams. only the lightest lubing is
needed. Thick grease will cause histerysis (back lash) making the RF
impossible to use. This is a problem with old RFs, especially if they
were over lubed at some time. The gummy lubrication makes them sticky
and irregular.
Good luck. If I've missed anything post back.
---
Richard Knoppow
Los Angeles, Ca.
dick...@ix.netcom.com
jon wells
and paste. I'm still unsure of something. If you follow the link
http://www.graflex.org/speed-graphic/kalart-manual.html
on page 8 the manual shows a press camera with the door open, and a
measurement of 6.75" from the bottom of the camera to the RF. What is the
significance of that measurment?
Also, I have a 135mm lens on 4x5 which references 3.5'. Does this mean that
given this lens, I position the lens 3.5' from the target instead of 4' and
move the sliders to obtain coincidence. Or do they measure different
things? Thanks in advance.
Richard Knoppow
>Richard, thanks a lot for all the instructions...I hope you only had to cut
>and paste. I'm still unsure of something. If you follow the link
>http://www.graflex.org/speed-graphic/kalart-manual.html
>on page 8 the manual shows a press camera with the door open, and a
>measurement of 6.75" from the bottom of the camera to the RF. What is the
>significance of that measurment?
>
>Also, I have a 135mm lens on 4x5 which references 3.5'. Does this mean that
>given this lens, I position the lens 3.5' from the target instead of 4' and
>move the sliders to obtain coincidence. Or do they measure different
>things? Thanks in advance.
>
>
>Richard Knoppow wrote:
>
>> jon wells <jwe...@slip.net> wrote:
>
I responded to an e-mail version of this message, its taken a couple
of days for the usenet version to get here.
The markings refered to are not distances but the arbitrary markings
on the setting scales inside the rangefinder. They are set to the
values on chart in the instructions as a starting point. Occasionally
they will be spot on for a lens but more often require juggling.
If you have a very early Kalart, the kind with the scales on the
outside, the starting values are somewhat different.
For 4x5 cameras the set up distances are; infinity, 15 feet, and 4
feet. The camera should also be checked at about 30 feet.
There are some differences for the early type finder. It has an
infinity adjustment in the center of the front scale. Its done by
loosening the hex head screw there and sliding it. The RF shold be set
up so it is coincdent at infinity with the actuating shaft not quite
all the way toward the infinity side. The RF should indicate infinity
with the focus track cranked out just a little from its back stop,
about 1/16th inch.
Other than this setting, and having slightly different numbers for
the starting points, the set up for the early RF is the same as for
the later model.