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Develop by inspection

 
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Les



Joined: 09 May 2001
Posts: 2682
Location: Detroit, MI

PostPosted: Sun Dec 02, 2001 9:38 pm    Post subject: Reply with quote

Does anybody know how to use a desensitizer when developing by inspection?

The chemical pinacryptol green is stuck in my head but I don't know the concentration/dilution, nor where I can find it (Photographer's Formulary doesn't stock it)

A friend of mine uses something called D-tek. But won't say how or where he gets it.

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jdman



Joined: 13 May 2001
Posts: 302
Location: Midwest

PostPosted: Mon Dec 03, 2001 12:39 am    Post subject: Reply with quote

Go to Goggle, and search for pinacrytol and there are a lot of articles about using pinacrytol yellow as a de-senersizer when developing sheet film. Apparently used in the 30's and 40, for developing panchromatic film with a safelight. This subject is way beyond my capability, but maybe this will help. Russ
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jdman



Joined: 13 May 2001
Posts: 302
Location: Midwest

PostPosted: Mon Dec 03, 2001 12:41 am    Post subject: Reply with quote

Sorry mispelled pinacryptol. Russ
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45PSS



Joined: 28 Sep 2001
Posts: 3210
Location: Mid Peninsula, Ca.

PostPosted: Fri Dec 28, 2001 5:11 am    Post subject: Reply with quote

Les, check The Darkroom Cookbook by Stephen G. Anchell, focal press, chapter 11.

Antec (bulk chemicals), 721 Bergman Avenue, Louisville, Ky. 40203; 502-636-5176, Fax: 502-635-2352.

Inspection Formulas:

Basic Scarlet N (for use with MQ developers)

Chrysoidine 15 grains | 1.0 grams
*Phenosafranine 15 grains | 1.0 grams
Distilled water 6 1/2 fl oz | 200. ml
Alcohol 1 1/4 drams | 5.0 ml

*Safranine-O, a derivative of Phenosafranine, may be substituted in the same amount. Safranine-O is considerably less expensive and more active.

To use, mix 1 part of the stock solution with 50 parts water. Soak the film for 2 minutes, and then transfer to the developer without rinsing. After 2 minutes in the developer, a yellow-green safelight (Kodak #3) can be turned on. Some workers leave the safelight on; others orefer to inspect the film for 10 to 15 seconds at 1 minute intervals.

NOTE: A variation of Basic Scarlet N, called DE-Tec, developed by Dr. Kevin Pernicano, is available from Antec.

Photographers' Formulary (bulk photographic chemicals and kits), P.O. Box 950, Condon, MT 59806; 800-922-5255.

Pinakryptol Green:

Photographers' Formulary sells a premixed solution in 100 ml quantities. If you purchase the solution from the Formulary, do not dilute any futher. Follow their directions and use as is, directly out of the bottle. Use at least 500 ml.

The following is the correct mixture to make the stock and, subsequently, the working solution from the powder.

Pinakryptol green 15 grains | 1.0 gram
*Water to make 16 oz | 500.0 ml

* A 50/50 mixture of water and alcohol will improve the keeping qualities of the stock solution.

To use as a forebath, dilute 1 part of the stock solution with 9 parts water. The film is desensitized for 2 minutes with the room in total darkness, then rinced, and finally transfered to the developing solution. Inspection should be carried on by either of the two methods detailed for Basic scarlet N.

Pinakryptol green can also be used directly in some developers, particularly pyro. To use in the developer, dilute 1 part of the stock solution with 30 parts developer. After 2 minutes in the developer, the safelight can be turned on. This procedure should not be used in developers that contain more than 1 gram per liter of hydroquinone.

Direct copy form The Darkroom cookbook with mininal editing.


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[ This Message was edited by: 45PSS on 2001-12-30 19:54 ]
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