[LargeFormat] Bad Kodak Lens

[Richard Knoppow]

----- Original Message ----- 
From: "Mike Kirwan" <mkirwan@pacbell.net>
To: <largeformat@f32.net>
Sent: Saturday, March 13, 2004 8:49 PM
Subject: RE: [LargeFormat] Bad Kodak Lens


> Richard:
>
> I repaired and refurbished my Baby G about 2 years ago.
The effort was
> well worthwhile and it is a truly flexible camera capable
of excellent
> results. I did make one modification and that was to
reverse the front
> standard so now I have a downward tilt. Great for
extending depth of field
> in landscape work.
>
> I have the 105mm f3.7 Ektar and the results are
outstanding. I also have a
> number of other Ektars and Commercial Ektars and they are
also excellent
> and can pretty much keep up with more modern lenses. I
wonder if yours was
> damaged (dropped?) that may the causing the problem, I
wonder as Kodak for
> its time had really good quality controls in place.
>
> There is a little secret about these Baby's, you can now
easily buy sheet
> film for them, and at least two emulsions are available,
both giving
> excellent results. Shh, keep this quiet as I am looking
for more film
> holders :-)
>
> - Mike
>
  Mine is the earlier Miniature Speed Graphic. These were
built from 1938 to 1948 when it was replaced by the camera
you have, one of the Pacemaker series. The Mini S.G. was a
sort of mixture of the "pre-Anniversary" and Anniversary
models having some features of both. This is a very nice
size and makes negatives large enough to have much of the
large format quality with low weight and bulk.
  I suspect the lens may be a mix of cells parts from two
lenses. For one thing, its problem would be apparent to
anyone trying to set it up with a rangefinder. It would have
had to get through Kodak's evidently good Q.C. _and_
Graflex's Q.C. In any case, I can probably find another, or
a good Optar, at one of the local camera sales. I will bring
my magnifier and pencil flash to the one this coming Sunday
at Buena Park.
  I had to replace the beam splitter mirror on the
rangefinder, plus the ground glass in the camera. One of the
buttons that the bed support struts runs on had been moved
and had a very crude patch made of wood filler under it. I
was able to remove most of the filler and put an inlay of
thin Mahogany in its place and remount the button. The
Mahogany came from a hobby shop in Pasadena that specializes
in model railroad supplies. This is stuff you can get for
less than a dollar to maybe a couple of dollars. The reason
for moving the button is that the misplacment caused the bed
to be twisted slightly and unstable.
   It turns out that replacing the beam splitter mirror is
not difficult. I used the material from Edmund Scientific
recommended by Ed Romney in his article on the Graflex web
site. The blanks used to cost about $30, they are now $15.
You can make many mirrors from one. I used a carbide scriber
from Home Depot, about $8.00. The scriber works a lot better
than the ususal wheel type glass cutter, which should not
even be tried on the mirror material. I also used it to cut
the ground glass. Cutting glass is not difficult but takes a
little practice. You must be very definite about scoring.
  The beam splitter mirror is held in place by two flat
spring clips. The assembly is held in the rangefinder by two
screws. Its much simpler to remove the assembly. In my
rangefinder the mirror was not cemented in place but there
were signs that it probably was. I suspect the cement is
canada balsam but don't know for certain. In his article
Romney says he has to break out the old mirrors, I don't
thing this should be necessary. The spring clips did seem to
have some adhesive at their ends. This came off with
Isopropyl alcohol. Canada Balsam or other light cements
should come off with either alcohol or Acetone. In any case,
the clips slip off the ends of the mirror frame and the
mirror just falls out. The old mirror is useful as a pattern
for cutting the new one. The new mirror is simply placed in
the frame and the clips put back. I fastened the ends of the
clips and the edges of the mirror with airplane cement. Some
care is necessary to make sure that the mirror side of the
beam splitter faces the peep sight window of the
rangefinder. Since it is a 50% mirror this requires a
careful inspection. You can tell the correct side by holding
a bright object near the mirror. There will be two
reflections on either side but on the correct side the first
or nearest reflection will be significantly brighter than
the other. From the back the two will be about the same. The
mirror bracket must be re-installed so it makes an exact 45
degree angle with the body of the rangefinder. One can make
a simple protractor to line it up.
  This all worked pretty well. The new mirror produced a
well differentiated center image where, with the old one, I
could hardly see it. This applies to late Kalart type-E
rangefinders, with a prism at the bottom but probably also
applies to the lower cost version with a flat mirror at the
bottom.

 I will post more later.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com