From: Richard Knoppow (dickburk@ix.netcom.com)
Date: 07/31/03-04:45:48 AM Z
----- Original Message -----
From: "Yu rei" <nanocrystals2003@yahoo.co.jp>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, July 31, 2003 2:18 AM
Subject: Lantern slide HIGH LIGHTS
> Hi.
>
> Does anybody have any information on a popular, good,
> "trade standard" lantern emulsion? I an trying to put a
> manufacturers name name and a lantern slide emulsion
> together: Seems they were already extinct by the time I
> was born.
>
> Did Kodak and Agfa both make lantern slide emulsions? what
> were their names? Anyone use any of these products? Does
> anyone have any data sheets or other technical information
> concerning lantern slide emulsions?
>
> I have prepared an experimental transparency emulsion, but
> the highlights are slightly veiled. I can bring it under
> control, but would like to have a specfic range to aim
> for. (So I will know it when I get there.)
>
> Actually, so far I am just looking at the density on
> paper, I beleive that the density is doubled in paper
> prints... is this correct? for both the highlights and the
> shadows... if so, it may not be such a problem once I get
> to the emulsion on glass. (They are waiting to be exposed
> and developed right now)
>
> Anyway, the problem is I need to know more about what is
> typical for this kind of emulsion.
>
> Does any one have D-MIN and D-Max data for any (good)
> lantern slides?
>
>
>
> Ray
>
>
Kodak made both plates and films for lantern slides.
Kodak Lantern Slide Plates were available in medium and
high contrast emulsions. The contrast was further adjustable
by coice of developer. These plates were about as fast as
medium speed enlarging paper. Kodak gives a film speed of
ASA 1.5 for the medium contrast plate.
The same emulsions were available on saftey base film.
Maximum density is from about 2.0 to 3.0 the high contrast
material having the higher density.
Kodak also offered Kodachrome in suitable sizes up about
1951 when Ektachrome became available.
Up to recently Kodak offered Kodak Fine Grain Release
Positive in sheet sizes. I think these have become
discontinued but may still be in stock somewhere. FGRP is
about equal in speed to fast enlarging paper (Kodabromide)
and is handeled similarly. Contrast is variable over a wide
range by choice of developer.
Ansco/Agfa also offered a similar film.
I don't know when lantern slide plates and films were
discontinued, they are still listed in a 1957 Kodak film
data booklet but are not shown in the 1975 edition of the
Photo-Lab-Index. However, that book has FGRP in it.
You are right that the light must pass through the
emulsion of paper (reflected light) prints twice. Also, the
density of transparencies must be higher since the the
illumination is usually considerably brighter than the
ambient, especially for projection. Actually, paper
emulsions are capable of considerably higher densities than
are usable in normally illuminated reflection prints. Try
looking at a good print by transmitted illumination.
Usually, you will find detail in the shadows which is either
invisible or hard to see when viewed normally. A properly
exposed print can be illuminated by very bright reflected
illumination, in a light box, and look very much like a back
lighted transparency. Such a print will look very high
contrast and too dark when viewed normally.
Slides larger than the usual 35mm are very impressive.
Large color slides will knock your socks off.
--- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com
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