Re: Camera film for enlarged negatives?

From: Etienne Garbaux <photographeur@softhome.net>
Subject: Re: Camera film for enlarged negatives?
Date: Sat, 28 Aug 2004 16:33:42 -0400

> The high speed and panchromatic sensitivity will make life difficult, but
> not impossible. First, your exposures will be very short. Just finding a
> timer that accurately resolves these short times is not easy. Also,
> enlarger lamps don't come on instantly. The on and off times of
> incandescent lamps may be longer than your exposures, making exposure times
> hard to determine and erratic. Cold-cathode lamps take a while to come on
> and stabilize -- maybe longer than your exposure, and quite variable. So,
> what you'd really like to do is use a lens with a shutter and leave the
> enlarger lamp on (all of my enlarging lenses are shutter-mounted because I
> used to do a lot of masking work). But this has its own problems -- the
> enlarger needs to be completely light tight, because the film is so fast
> that ANY light leakage will fog it. You also need to use a flat black
> backing on the easel to prevent halation. These are not insurmountable
> problems, but it is definitely more effort than using copy film.

I keep a 135mm lens on Copal selt setting shutter on my enlarger to do
quick sensitometric tests on emulsions. Nothing expensive -- they are
135mm Tominon copy lens that fits on Copal shutter, the whole thing
came from Polaroid Land MP-4 copy camera that was waiting to be thrown
away. (That's what it was when I followed someone who told me an
enlarger was being thrown away.) Yes light leaks are a bit of
trouble. But it can be fixed without too much work. You can also use
light meter as a illuminance or luminance meter. Calibration factor
for Sekonic L-408 is printed in the instruction manual. I'm not sure
if other manufacturers print those, but they should be able to tell
you.

--
Ryuji Suzuki
"You have to realize that junk is not the problem in and of itself.
Junk is the symptom, not the problem."
(Bob Dylan 1971; source: No Direction Home by Robert Shelton)