Positive development

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Hi:

Would it be possible to develop an exposed photopaper positive. The benefit would come when creating a paper 'negative' in a pinhole camera. Rather than making a contact print to get the final picture, wouldn't it be an interesting technique to develop the image positive ?

-- Marc Leest (mmm@n2photography.com), October 17, 2000

Answers

I'm not sure I understand your question. But if you're asking whether it would be possible to place photographic paper in a pinhole camera and make a negative and then make a positive from that negative -- yes. If you're asking if one could make a positive in this way -- don't see how.

-- Christopher Hargens (ldmr@cruzio.com), October 17, 2000.

I suppose a cibachrome (or whatever that is called now) could make a direct print in a pinhole camera. I don't know that there are positive B&W papers.

-- Paul Oosthoek (pauloosthoek@hotmail.com), October 18, 2000.

How about simply using Polaroid film?

-- Brian C. Miller (brian.c.miller@gte.net), October 18, 2000.

This is certainly possible. I am not sure about the chemisry, but it would work like the TMax Reversal Kit. Basically, you would develope the negative image, bleach it away, expose the paper to light and redevelope the positive image.

Has anyone done this?

-- Ed Farmer (photography2k@hotmail.com), October 18, 2000.


I'm sure you can still get direct reversal materials. These are papers or films that have been pre-exposed to their maximum density. Further exposure results in true solarization, so you end up with a positive. I know such materials at least used to exist, but I've never used them, and I don't know what the tonal range is like. I imagine the contrast is very high.
Try searching Kodak's website.

-- Pete Andrews (p.l.andrews@bham.ac.uk), October 19, 2000.


You can develop B&W paper to form a direct positive image by using the following method (I found this formula online and tried it to verify that it works; however, I have not done it enough times to fine tune the process):

1. Develop the paper as you normally would (e.g., Dektol or whatever developer you normally use). 2. Bleach the paper in a dichromate bleach solution (9.4g of potassium dichromate + 12ml of sulfuric acid per liter of water) for about 1 minute. 3. Re-expose paper to a diffuse light source (room light). 4. Re-develop the paper. 5. Stop bath. 6. Fixer. 7. Wash.

Another option, and the one that I prefer for making B&W prints from color slides without having to make an internegative, is to contact Photo Warehouse in Oxnard, CA (800-922-5484) and get some of their direct positive B&W paper. It can be used either for direct camera exposure or enlarging. It's fairly high contrast stuff and I have found that in order to get acceptable contrast when enlarging, I have to give the paper a pre-enlargement flash exposure to room light for about 1 second to bring down the contrast. It can be developed in any standard B&W chemicals.

Good luck in whichever option you try.

-- Larry Rudy (ljrgcr@cetlink.net), October 26, 2000.


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