[LargeFormat] Anyone Home???

[Stuart Phillips]

Richard, another amazing answer that goes in the "keeper" file. Thanks for
your erudition.

----- Original Message -----
From: "Richard Knoppow" <dickburk@ix.netcom.com>
To: <largeformat@f32.net>
Sent: Wednesday, December 04, 2002 8:39 PM
Subject: Re: [LargeFormat] Anyone Home???


>
> ----- 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
>
>
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