[pure-silver] Re: NC Film?
- From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Tue, 10 Jun 2008 15:10:33 -0700
----- Original Message -----
From: "Ray Rogers" <earthsoda@xxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Tuesday, June 10, 2008 9:58 AM
Subject: [pure-silver] NC Film?
Richard, anyone...
Do you recall a film called "NC"?
I thought it just meant 'non-curl' but perhaps there was
another meaning.
I found a statement that it developed contrast differently
than verichrome film and was wondering what it meant... if
it meant it had a higher contrast or higher speed in the
highlights.....
Ray
Kodak NC was the box camera film before Verichrome NC
means Non Curling: the film was either the first or one of
the first to have a gelatin back coating to counteract the
shrinkage of the emulsion.
I may have some data on NC film in a very old Kodak
guide book, I'll look. NC film was made before there was any
standardized speed rating method but the exposure guides for
old film allow one to make a pretty good guess as to speed.
Most of these old (1920s and early 1930s) films would be
around ISO-25 by modern rating. I think NC was
orthochromatic but it may have been color blind film or only
slightly ortho.
I also don't remember the exact date Verichrome came on
the market but it had improved green sensitivity compared to
previous orthochromatic films, hense the name. Pan films
were available as early as 1900 but the early ones were not
very good. The real impetus for good pan films came with the
requirement of the motion picture industry for them when
sound was introduced. Because the formerly used mercury arc
and carbon arc lamps were too noisy for sound the industry
had to switch to tungsten lights. These had lower overall
output but also a different spectrum concentrated more
toward the red end of the spectrum. The formerly used
orthochromatic films were just too slow.
Ortho films have an advantage for box cameras: their
limited spectrum eliminates some of the bluring caused by
the lack of chromatic correction of the lenses. It also
allows processing under a deep red safelight. The first film
I ever developed was Verichrome and was done in a tray under
a "ruby lamp".
I don't think Kodak ever published a time line for its
films. There was a booklet listing the dates of introduction
and discontinuance of roll film but that is not the same
thing.
Kodak also likes to recycle trade-names, for instance
the use of Ektar, originally for its deluxe lenses, was
reused for a color film. They also like the name Royal and
the use of X in names. Some film names were reused for quite
different films, Kodachrome and Kodacolor being examples.
Enough, my carpal tunnel problem is bugging me.
---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx
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