[alt-photo] Re: Creating Film Negative by Enlarging a Film/ Slide Positive

[Geoff Chaplin]

Well here's my two pennyworth.

I generally used in camera 8x10 negs but over the last couple of years have
enlarged 35mm up to 16x24 for gum printing. I've tried the following
methods:
A. Reverse process B&W file (easy but lengthy) and print onto (e.g. FP4+)
film.
B. Neg -> enlarged print -> contact print onto (film, lith film, paper)

Out of the second set of steps printing onto paper is easiest but has a
limited tonal range and leads to slow printing times. This can be speeded-up
a bit if you print onto fibre based paper then oil the back (any clearish
oil will do. Printing onto film is OK but I find difficult to judge - a
densitometer helps. Generally I print onto lith film partly because it's
cheap and robust. But the downside is development and resulting contrast
range. I think I've tried everything that’s suggested on APUG and elsewhere
and find the best continuous tone developer is dilute paper developer about
1/4 strength. It oxidises very quickly so you need a fresh batch every
half-hour or so. Sometimes its necessary to make two negs - highlights and
lowlights.

Of course scanning an digi-printing as a million times easier ....

Geoff Chaplin
チャップリン・ジェフ

geoff at geoffgallery.net
www.geoffgallery.net

Skype: geoffchaplin1611
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-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of
Francesco Fragomeni
Sent: Monday, June 04, 2012 1:11 AM
To: The alternative photographic processes mailing list
Subject: [alt-photo] Creating Film Negative by Enlarging a Film/ Slide
Positive

I'm interested in enlarging positive film (any slide/ chrome film or B&W
reversal processed film) onto a larger piece of traditional B&W negative
film (not lith) for the purpose of producing enlarged negatives suitable for
alt-process and Azo. I know people do this but I've had a difficult time
finding a solid explanation and instructions for how to go about it since it
is far more common to scan these days which I am very aware of but not
interested in with this particular case.

Basically, can I expose/ enlarge slide (positive) film onto regular B&W
negative film and achieve an enlarged negative? Is the higher contrast of
slide film helpful in this situation or a hinderance? Would it be better to
contact print B&W negative film (much lower contrast) onto another piece of
B&W neg film to produce a positive, develop to the same contrast as the
original, and then enlarge that lower contrast film-interpositive onto a
larger sheet of B&W neg film to achieve the enlarged negative?

I'm interested in this specific process of enlarging film positives to
larger negatives, not the alternatives so lets please try to stay on topic
and not go astray with conversations of digital negatives, duplicating film,
etc., although if reversal processing your original B&W neg to positive
plays a role that might be worth explaining.

Thank you!!

-Francesco Fragomeni
www.francescofragomeni.com
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