[LargeFormat] Anyone Home???

[Richard Knoppow]

----- Original Message -----
From: "hairy possum" <pleohmy@yahoo.com>
To: <largeformat@f32.net>
Sent: Sunday, December 01, 2002 4:26 PM
Subject: Re: [LargeFormat] Anyone Home???


> Hey Richard,
>
> I guess folks are just full of turkey about now.  (:>)
>
> Do you have any information about the film and
> developer used by Edward Weston??
>
> Are there any films on the market that would resemble
> the film used by him???  I read somewhere that Efke 25
> and 50 were old style emulsions, but that the 100 was
> the new type.  Do you know whether or not this is
> true???
>
> I love the look of his photographs, and want to try
> and get that same/or close look in my photos.
>
> Any info on the film, paper, chemicals, etc. would be
> appreciated if you can help.
>
> Thanks in advance,
>
> Lauvone
>
> =====
> www.Lauvone.com
>
  I'm never sure what people mean by "old style" emulsions.
There were many changes in emulsion making even during the
1930's. From some fairly early time, and I don't know a date
but probably the early 1930's, it was common to coat film
with two different emulsions in separate layers. One being
slow and high contrast, the other fast and of low contrast.
The combination was used to establish the shape of the D
logE curve and to extend the latitude. This system works but
the thicker emulsion coatings result in more scattering than
a single emulsion. However, there may still be some double
coated films being made.
  About the mid or late 1950's some new films came out with
extra thin, single coated emulsions. These films had much
better resolution than thick emulsion film do to the
elminination of much of the light scattering, but tended to
have limited latitude.
  There have been many other changes in emulsions over the
years.
  Some films made now which are supposed to be "old
fashioned" are not. For instance, Agfa APX films are quite
modern. They have relatively thin single emulsions and also
have anti-halation coatings under the emulsion rather than
as a back coating, the method used for color films.
  There was pretty rapid development of sensitizing and
grain control technology during the 1930's. Agfa caught
Kodak off guard about 1936 with the discovery of Gold
sensitizing. This allowed Agfa to just about double their
film speeds with no increase in grain size. Kodak caught up
pretty fast.
  If you have access to Turner Classic Movies on cable, you
can see some of the change in film in the change in
pictorial and sound quality with time. Now, one must be
careful here since some of the prints were made from
material many generations removed from the originals, but
most of the MGM movies look and sound pretty much like the
original issue prints. There were tremendous advances in
sound recording film made about the late 1930's. Not all the
difference in the sound was due to the film bug a lot of it
was. Also, new much finer grain release positive film came
out in the late 1930's. In original issue prints the
difference is obvious.
  Sound quality depends a lot on the way the sound is
transferred so quality of the TV prints is not always
representitive of the original, but in many cases its pretty
close.
  Probably the worst sounding films are from RKO. I think
this may be due to having duplicated tracks to work with
although some of the "clippy" quality is characteristic of
RCA recording. This is pretty far afield but much work on
film characteristics and sensitometry was done with regard
to photographic sound recording. It is very sensitive to
scattering of light in the emulsion irradiation) and
consequent image spread. It also requires high resolution
and little edge effects. In addition, there is a distinct
problem with receprocity effect since exposures can be as
short as 1/10,000 second.

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