Re: pyro developed negs for cyanotype?

Hi Diana,

Don't know if you have already tried what I'm suggesting below but will
write anyway (please forgive if you already know and/or tried these
workarounds...)

What formula were you using (classic or new cyanotype)? Have you tried acid
development (white vinegar, 5% glacial acetic acid, 5% - or stronger -
citric acid)? If the negatives are too contrasty for straight cyanotype
formula (old or new doesn't matter) developing in acidic water may decrease
the contrast of the paper (even you can try to add some acid to the coating
solution... others: does this sound like a good solution?)

If the problem isn't solely based on some sort of UV-blocking film base,
acid development may certainly help - along with prolonged exposure times of
course. But if the contrast is too high, even this modification may not
help. Another point that comes to my mind: maybe you have to try
intermittent exposures if you're using flourescent tubes. If they get too
hot, their UV output is greatly reduced - which means that increasing the
exposure times by 2 stops may not translate to a "real/practical" 2 stops
increase...

Regards,
Loris.

----- Original Message -----
From: "Diana Bloomfield" <dhbloomfield@bellsouth.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Monday, November 01, 2004 12:27 AM
Subject: Re: pyro developed negs for cyanotype?

> Thanks, Joe. This was Fujifilm, but I've never used b&w 4x5 Fujifilm, so
> I don't know how new it is, or whether it is suffering the same fate with
> the film base as TMAX 100, but it sounds like it. A 4 hour exposure would
> have been about right, I think!
> ...
Received on Sun Oct 31 17:25:55 2004