Re: direct positive B&W paper

hello.
this info is from http://www.rit.edu/~andpph/photoforum.html
i don't have tried it but seems a good method.

Note 15.07 < Reversal Processing of Black and White paper >

PROCESSING ENLARGING PAPER AS A POSITIVE

...means you can use the paper in a camera and make one-of-a-kind images...
...roughly collected from info seen in various rec.photo postings...

If you use the paper as a material in the camera then you may wish to
consider using Panalure for "normal" looking results in terms of tonal
reproduction.

This is becasue normal B&W papers are not sensitive to red and thus anything
colored red in a scene will turn out very dark or black.

You can also make B&W prints directly from slides this way. Place a slide in
the enlarger and project it onto B&W paper. Again, to maintain more natural
looking tones use Panalure.

The chemicals and processing steps are as follows:

1. First Developer 60-90 sec.
2. Rinse 30 sec.
3. Bleach R-9 30-60 sec.
4. Rinse 30 sec.
5. Clear CB-1 30 sec.
6. Rinse 30 sec.
7. Expose to light 40 W bulb for 5-10 sec. at 12 inch
8. Second Developer 30-60 sec.
9. Fix 30-60 sec.
10. Wash Normal paper washing time
11. Dry

First Developer: The original literature referring to this method of making
positive prints from slides is Kodak Publication G-14, "Direct Positive
Photography". You can probably get a copy of it by calling the Kodak Hot
Line at 800-242-2424. In any case, that booklet specified a high contrast
developer such as D-88. Dektol or D-72 dilited 1:1 can probably be
substituted successfully for D-88.

Rinses should be under running water, or at least two changes in the 30
seconds.

The bleach is modified Kodak Bleach R-9:

· Water 800 mL
· Potassium Dichromate 9.5 g
· Sodium Bisulfate 66 g
· Water to make 1 L

Clear CB-1:

· Sodium Sulfite 90 g
· Water to make 1 L

Second Developer can be Dektol again. Or if you want a sepia toned print,
skip the light exposure and use Sulfide Redeveloper T-19 (Sodium Sulfide 20
g with water to make 1 L).

As with any positive process, the resultant density value is opposite from
ordinarily processed paper: More exposure = lighter print, less exposure =
darker print.

good luck, i wait for your results

Manuel

----- Original Message -----
From: "Jack Duganne" <duganne@earthlink.net>
To: <pinhole-discussion@pinhole.com>
Sent: Tuesday, November 27, 2001 5:55 AM
Subject: [pinhole-discussion] direct positive B&W paper

> Anyone have any info about direct positive black and white papers or a
> method for developing any b&w papers to be positive after development?
> I used to use an old Kodak paper but can't remember the name and it had
it's
> own chemistry. I would love to do large format or even mural size using
> this process - whatever it is!
> I like to use Ilfochrome for color now, but have lost the access to bulk
> purchase of the papers and chemicals that I used to have. Any help there?
> thanks for any help you might have...
>
> jack
>
>
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Received on Tue Nov 27 04:18:53 2001