From: Richard Knoppow (dickburk@ix.netcom.com)
Date: 07/18/02-05:06:55 PM Z
At 11:47 PM 07/18/2002 +0100, you wrote:
>What about raising the developer pH by adding (for example) some carbonate?
>(And maybe some bromide if fog rises too much)
>
>
>
>Liam
>
>-----Original Message-----
>From: Shannon Stoney [mailto:shannonstoney@earthlink.net]
>Sent: 19 July 2002 00:11
>To: alt-photo-process-l@sask.usask.ca
>Subject: finally: a good HP5+ negative
>
>
>I finally succeeded in making a good negative for cyanotype with HP5+ today.
>I processed it for 20 minutes at 85 degrees. I shot it at 3200 in my
>pinhole camera. The subject was a test scene that I set up, with a gray
>card, a piece of denim which measured two stops darker than the gray card
>for zone III, and a white plastic chair which was zone VII. The denim
>measured .31 and the chair 1.86. This is close enough for government work.
>But again, if the contrast of the scene was low and development needed to be
>expanded further, it would be difficult, I think, without simmering the film
>on the stove or something for half an hour or so!
>
>--shannon
>
Since Shanon is using D-76 (I think she said) she can add Borax. Up to
ten times the normal amount of Borax can be used (20 grams/liter). Packaged
D-76 is buffered with boric acid so adding Borax will not raise its
activity quite as much as it will the original formula, but there will
still be a noticable increase. The trade off is grain. Adding about 0.5
gram/liter of Kbr to D-76 will result in very slightly higher film speed.
This applies to unused D-76, after developing film in it there will be some
bromide from the film.
---- Richard Knoppow Los Angeles, CA, USA dickburk@ix.netcom.com
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