RE: Reversal processing for enlarged negatives

Loris,

If your original neg prints OK on bromide, I don't think it is *normal*
to be getting a very grainy enlarged neg. At the moment I'm at a loss,
but maybe we should be looking for some obscure reason. I've
encountered many weird and wonderful faults working with reversal (as
well as other processes!) and once had a soft, vaguely grain-like
pattern on my films. Had me baffled for a time, but finally figured it
out: I was doing a number of enlarged negs, exposing and flashing the
films one night and processing them the next (this was when I was doing
a "calculated" flash). Between the two sessions the film went into an
old paper box, but not in a black plastic bag; a small amount of light
leaked through the lid (which I thought was opaque - it was with bromide
paper!) - not enough to have a noticeable impact on densities, but
enough to project a pattern of cardboard paticles onto the
lightly-exposed areas of film, where the exposure would have been around
the threshold value. Perhaps think about each step in what you're
doing, to see if you can identify some such cause.

As for D-19, you may well discover something I don't know but to avoid a
high fog level it is crucial that the first development is complete -
i.e. right down to the film base. To achieve this in a reasonable
amount of time, a vigorous developer is necessary; paper developers do
this pretty well (but don't use warm-tone) but I would guess that you'd
have to increase your dev times with D-19, maybe substantially. What I
had hoped to do - not too successfully? - was to make the reversal
process as simple as possible, and I believe it should be possible to
get good results using the "standard" chemistry (i.e. a print dev), thus
avoiding unnecessary complications.

OK, some lith films might be different and one or two - that I haven't
met - might be unsuitable, but of all the films I tried, the longest
first development time necessary to get down to the film base was about
5 minutes in working strength print dev. I don't remember which film
this was now, but 3 minutes was adequate for most of the other films.
In my article, I recommended 6 minutes in working strength print dev
(didn't I?) to cater for the film that needed the longest, plus a safety
margin; it doesn't really matter if this results in overdeveloping
certain other films because the exposure is tailored to suit them.
(Yes, results might be a little different and perhaps even better if
each film could get exactly the time it needed, but I considered it
important to exclude dev time as yet another variable in the process,
hence suggested each film get the same "safe" time, which I expected
would be long enough for any lith film.) I also tried several print
developers (non warm-tone) and found this recommendation was applicable
to all of them.

If we can assume that your development is adequate (which it conceivably
might not be, depending on the film you're using), my suggestion for
your next test would be to increase your through-the-negative exposure.
Maybe this isn't long enough to ensure development down to the base in
the development time you're using, and maybe this is because one of the
things you have to do is judge the exposure for a "normally-exposed
positive" before applying an exposure factor. If your idea of normal
exposure is different to mine (i.e. you'd prefer a lighter positive than
me), this could be causing you to give less exposure than I would in the
same circumstances. That's maybe a weakness of the method, but try just
one test with, say, double your normal exposure time and see what
happens (leaving the flash time the same).

D-19, with or without thiocyanate? Worth trying, and could be an
improvement - it's all useful experience even if it isn't. However, I
believe quite a few people are using this method successfully and
without the kind of elaborations proposed by Ryuji. How about some
(honest!) testimonials?

A final thought. If you're going the D-19 route, maybe see if it'll
work well enough on camera film to produce a positive that can be
enlarged onto lith and developed with Dave Soemarko's LC-1. Maybe there
are some commercial reversal kits for camera films.

Liam
Received on Thu Mar 25 13:11:37 2004