Re: Enlarged negatives from transpareny

William Patterson (wpatterson@ASAP.Bus.Wisc.Edu)
Mon, 10 Nov 1997 16:08:09 -0500 (CDT)

On Mon, 10 Nov 1997, Chris Gibbs wrote:

> Hello All,
> ...
> Instead of going back to the old methods :-) and shooting a medium/large
> format monochrome image in addition to the tranny I have a question.
> "Does anyone out there produce enlarged negatives directly from a
> transparency"? My thought (as a novice Alt.Photo person) is that the
> results should be very good if working with a fine grain medium format
> tranny and enlarging onto say 8x10" FP4+.
> ...
You can produce an enlarged negative from a transparency. The problem
that you run into is that most transparencies have a density range that is
much higher than a B&W negative used for normal printing.

To print on a normal grade 2 paper, an ideal negative whould have a
density range of about 1.0 or 1.1 for use with a diffusion light source.
If you simply project a transparency onto negative film or contact print
it, then the resulting negative will have a much higher density range.
If you are using an alternative process that requires much more contrast
images, then this simple method may work for you.

You should be able to measure the density range of the transparency using
a densitometer. You simply read the density of the lightest area where
you want detail to show and the darkest area where you want some detail
to show and subract the two readings. This gives you the sensity range
of your transparency.

If the density range of your transparency is close to the density range
that you need for your final print material, then you might want to try
to simply enlarge the transparency and make a print. If it is a little
off, then you can probably adjust the density of the negative by changing
the developing time, just like a photographer using the Zone System does.

If the transparency has a much larger density range that you need, then
you might want to consider using a contrast reducing masking technique
when exposing the negative material. Bob Pace, a retired professional
printer (Ilfochome and Dye Transfer) sent me a color copy of an article that
he published that explains how to use contrast masking to make negatives
from transparencies suitable for printing on normal B&W paper.

Bob shows how to use contrast reducing masks to not only match the
contrast to what is needed but also adjust the interpretation of the
colors in the transparency using color separation filters when exposing
the contrast reducing mask.

I'm currently working on making some negatives from lantern slides using
Bob Pace's techniques.

Bob Pace can be reached via E-mail at BPace10552@aol.com. He has written a
number of books about using masking to reduce contrast and about other
techniques. His latest book describes how to make enlarged separation
negatives for the Ultrastable color printing process.

Good luck,

Bill Patterson