[pure-silver] Re: Bulb for Focomat IIc
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: "Pure-Silver Free" <pure-silver@xxxxxxxxxxxxx>
- Date: Thu, 21 Dec 2006 14:46:46 -0800
----- Original Message -----
From: "Gary W. Marklund" <Gary@xxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Thursday, December 21, 2006 6:31 AM
Subject: [pure-silver] Re: Bulb for Focomat IIc
At 12:26 AM 12/21/2006, you wrote:
Quoting "Gary W. Marklund" <Gary@xxxxxxxxxxxx>:
snip
> My 1C calls for an Opal 75 watt. So, I guess the 211 is
> what you want.
The Ic does not call for 75w (earliest documentation
suggested 75w given
heat and the very long exposures demanded by then
contemporary papers) but
is (in general) suitable also for 150w. Later versions
(more elongated, egg
like shaped, versus nearly round) were explicitly also for
150w and most
that saw commercial action got 150w bulbs (time was and
still is money).
My "manual" is a downloaded reprint of a 15 page document
titled
"focomat Ic Instructions for Use", Ernst Leitz gmbh
Wetzlar. Back
page says Branch Works: Ernst Leitz (Canada) Ltd,
Midland-Ontario.
List Photo No. 6095a/Engl. X/52/LX. Printed in Germany K.
Waldschmidt, Wetzlar.
Topic C on the top half of page 6 states "The 75 WATT BULB
normally
supplied and used in conjunction with the condenser lens
yields a
diffused illumination advantageous for miniature negatives
as
blemishes or dust particles on the back of the film are
prevented
from appearing on the picture and harmonious enlargements
are
obtained." Next to that paragraph is a diagram of the
lamphouse
showing a light bulb with the inscription "75 W Opal
Lamp".
Probably a misprint or it got scrambled during the
download, sorry.
Gary
I'm not sure which part of this is the suspected
misprint. FWIW, the PH-211 (75 Watt) and PH-212 (150 Watt)
are the same size (I have both for my D2V). The type numbers
were originally General Electric designations but have
become sort of generic. I do not often use the 212 lamp in
my enlarger because of the heat.
Most so called condenser enlargers are actually partially
diffusing due to the use of a large, diffuse surface, lamp
like the 211/212. Some condenser enlargers use true specular
sources and are completely collimated. These have the
advantage of producing very sharp images but are very fussy.
Any blemish on the original is very much exagerated; a means
other than the lens diaphragm must be supplied to regulate
intensity; the source must be focused for each change in
magnification; the source also exagerates contrast
substantially. Such sources are used mainly for special
purpose printing such as electron microscope negatives or
very large pictorial prints.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your
account (the same e-mail address and password you set-up when you subscribed,)
and unsubscribe from there.
Other related posts:
