Re: So where can I buy a optical printer???????

From: Myron Ort (email suppressed)
Date: Wed Aug 06 2008 - 17:01:08 PDT

all this talk about optical printers and my regrets about letting my
old JK go and the fact that the current models sell for a whole lot
more has me seriously thinking that a diy project might be fun and a
good challenge.

The crux of the matter is the "bed" which secures the camera and the
gate holding the frame to be filmed so there can be reliable
stability along with some adjustability, eg. some kind of "lathe bed"
or equivalent. A discarded Shopmate would be overkill but that is the
idea. I will keep my eyes peeled for the right piece of "junk" for
the bed.

The rest seems straight forward: a light source and whatever
extension tubes are necessary to get a frame in focus. Granted the
diy version might be more primitive regarding automated conveniences,
but not necessarily so, depending on one's ingenuity.
A single frame motor for the Bolex would be good to assure regularity
of exposure, but hand turning the projector advance might be ok
although another similar motor there could be a convenience but not
an absolute necessity.

Another funky diy way to go is filming from a rear screen. I have
done this years ago and didn't worry so much about the exact color
temperature of the 16mm projector bulb. The fear was always that with
the freeze frame clutch engaged in the projector a frame would burn,
however that never really happened. Mostly I re-filmed running loops
and used them in multiple exposures. They used to sell a very
convenient little rear screen unit with built in stand. You set up
projector on one side, camera on tripod other side.

Anyone know off hand, with the old B&H projectors, what exactly
happens when you engage that freeze frame clutch that keeps the film
from burning as it would if the frame got jammed in normal running.
Something seemed to be in play when you used that clutch that either
cools the bulb down or further insulates the film frame from the heat
of the bulb. Then there is the matter of color temperature change in
that freeze mode (not sure???).

What bulb does the JK use? I think it provides a meter for color
temperature calculation. How about substituting that bulb for the
usual type used in a projector. Is anything available with LED bulbs
which could possibly be utilized? Some LEDs are supposedly "tungsten"
temp. or close to it. I do know that with the old JK motor on a Bolex
that the exposure is long, 1/2 sec. shutter speed or so, and perhaps
a wimpy LED might work. Just don't know. Anyone experiment along
these lines?

just some ramblings....

Myron Ort

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