Re: pyro developed negs for cyanotype?

Thanks, Loris. We used the classic cyanotype formula. The white
vinegar bath did occur to me, along with diluting the sensitizer itself
at one point. The lights themselves get warm, but the lightboxes had
good fans that also kept the lights relatively cool (not hot), and the
other students were using the same lightboxes and having no problems
with longer than normal exposures. He also tried the sun. So I'm
thinking it's a combination of the Pyro and, perhaps, Fuji b&w has this
same UV blocking layer, like TMAX?
On Oct 31, 2004, at 6:25 PM, Loris Medici wrote:

> 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 17:46:02 2004