From: rspeirs@javelin.sim.es.com (Ron Speirs)
Subject: Re: B&W Slide film
Organization: Evans & Sutherland Computer Corporation
Date: Tue, 8 Sep 1992 16:58:17 GMT

In article <cicero.1ehp@hotcity.COM> cicero@hotcity.COM (Andreas Locicero) writes:
>In article <laks4sINNkcm@almaak.usc.edu>, ajayshah@almaak.usc.edu (Ajay Shah)
>writes:
>>
>>Now, after having had a lot of fun with a Nikon 6006 shooting (color)
>>slides, I'd like to try my hand at B&W slides.  What would you suggest
>>for film?  How is it processed?  Would Kodalux-as-usual work?
>>
>>What words of wisdom would you like to contribute on shooting B&W
>>slides for the first time after having done lots of color slides?
>>
>>Ajay Shah, (213)749-8133, ajayshah@usc.edu
>As far as I know, no one makes a black and white slide film anymore.  You must
>shoot a negative film and process it specially for reversal to get black and
>white slides.  This means doing the processing yourself or trying to find a pro
>lab willing to do it for you.
>
>I saw a reference in this newsgroup to processing Tmax for reversal, I an I
>have some experience with processing Panatomic X this way years ago. Kodak
>makes kits for such things Look in better camera stores.
>
>A.J. LoCicero >> cicero@hotcity.com
>

Here is how black-and-white reversal processing works:  

The First Developer is an ordinary high contrast negative developer with
a silver solvent (sodium thiocyanate or sodium thiosulfate) added to remove
just enough silver to produce clear highlights.  The film is then rinsed.
The Bleach (potassium dichromate with sulfuric acid or sodium bisulfate)
removes the *developed* negative image from the film, but leaves the
*undeveloped* silver halides intact.  The film is rinsed again and goes
to a Clearing Bath (sodium sulfite) which neutralizes any remaining bleach.
Then the film is either exposed to light or fogged chemically, which
makes the remaining undeveloped silver halides developable.  A Second
Developer, essentially the same as the first developer without the
halide solvent, develops the remaining "positive" image.  This is followed
by a standard fixer, wash, dry.  

Since the image is composed of the same kind of developed silver halides
as in a negative-processed film, I would expect the grain and archival
properties to be the same.  

There are several B&W films which can be processed to yield positives
(slides).  Unfortunately, the most common, Panatomic X, is discontinued.
However, two other thin-film emulsion films should work as well:  Ilford
Pan F and Agfapan 25.  Kodak Technical Pan and T-Max 100 will also work 
with the appropriate developer.  Following are recipes for 4 developers
and other solutions.  The first two, Kodak D-67 and Z-7 were for the Pan-X
film, and should be used for Pan F and Agfapan.  The next two are for
Tech Pan and T-Max.  I tried T-Max 100 film in the Z-7 developer; it didn't
look too good, so I would recommend that you stick with the developer
listed.  

As far as the other solutions go, I cannot explain the differences in
the formulas.  Since the bleach and second developer reactions go to
completion, I really don't think that the different formulas would make
much difference.  I would discourage the use of Sulfuric Acid in the bleach
because it is hazardous and hard for a private person to obtain.  The
Sodium Bisulfate works just as well.  Also, I wouldn't bother with the
FD-70a redeveloper; it only lasts an hour once mixed and light reversal
is easy enough and much cheaper.

FIRST DEVELOPER
			Kodak D67	Z-7	Tech Pan	T-Max

Metol (Elon)		2.0 g			4.0 g		2.0 g
Phenidone			    0.25 g
Sodium Sulfite		90 g	      34 g	 25 g		100 g
Hydroquinone		 8 g	     5.6 g	5.0 g		5.0 g
Sodium Carbonate Mono	52 g	      36 g	 30 g		 60 g
Potassium Bromide	 5 g	     1.6 g	2.0 g		4.0 g
Benzotriazole			    0.25 g	.03 g
Sodium Thiosulfate Penta 					 16 g
Sodium Thiocyanate 51%  3.0 mL	     4.0 mL	3.0 mL
Potassium Iodide 0.1%				 10 mL
Water to make		 1 L	       1 L	  1 L		  1 L
Time			 8 min	       6 min	 10 min		 10 min
Temperature F		68	      68	 75		 68


BLEACH

Potassium Dichromate	9.5 g	      11 g	9.5 g		9.5 g
Sodium Bisulfate		    22.9 g	 66 g
Sulfuric Acid		 12 mL					 12 mL
Water to make		  1 L	       1 L	  1 L		  1 L

CLEAR BATH

Sodium Sulfite		 90 g	      34 g	 90 g		 50 g
Water to make		  1 L	       1 L	  1 L		  1 L

SECOND DEVELOPER	
			FD-70a	    Same as	D-19		Dektol 1:2
				   First Dev
				   without
				 Thiocyanate

FIXER			F-5 or	     Usual	F-5		Usual film
			F-6	   Film Fixer			Fixer

Processing Schedule

First Developer		See times under formulas
Rinse			2 minutes
Bleach			2-3 minutes
Rinse			1 minute
Clear Bath		1.5-2 minutes
Rinse			1-2 minutes
Re-exposure		30-60 seconds each side
Second Developer	3-4 minutes
Rinse			30-60 seconds
Fixer			Normal time for fixer used
Wash			Appropriate time for fixer used, 10-20 minutes
Photo-flo Wash
Dry

___________________________________________________________________
Agitation in the solutions should be 5 seconds of every 30 seconds.
Re-exposure to light renders the remaining silver developable.  The use of
stainless steel or clear plastic processing reels makes it possible to
re-expose the film while on the reel.  Optimum re-exposure is about 800
foot-candle seconds, but the amount of re-exposure is not critical.  Both
sides of the reel should be exposed for 30-60 seconds to a 60 or 75 watt
bulb at 12 to 18 inches.  The reel should be rotated constantly during
re-exposure.  A 30 to 40 second exposure to a 40 watt fluorescent tube at
2 to 4 inches can also be used.  No variation in density will be apparent
until these exposure values are changed to about 1/10 or 10 times the
given amounts.

As can be seen from the formulas, the steps following the first developer
are not too critical; although the clear bath should not exceed 2 minutes.
Also, room light is OK after the bleach step.  I shot Pan-X (developed
in D-67 or Z-7) at ISO 80-100.  A similar modification in speed would
be expected for Pan F or Agfapan 25.  My source for T-Max indicates
ISO 100.  The Tech Pan was rated at ISO 40.  My sources also indicate that
D-67 can be made by adding 3 mL of Sodium Thiocyanate 51% to D-19 developer.

If anyone decides to try these formulas, be sure to shoot a test roll first
and bracket to find optimum exposure.  Since you will get a positive, follow
the exposure rules as for color slide film: More exposure = lighter, less
dense image; less exposure = darker, denser image.

I have not tried the Ilford XP-1 or XP-2 in E-6; you would get a positive
image, but I remember reading an article that said the results weren't too
great.

(P.S.  I saw a T-Max reversal kit in the local photo store for $30.  I
think this price is unjustified knowing what approximately what is in the
kit (the main ingredients are on the box).  Their older reversal kit for
Pan-X was only $15.)

Ron Speirs, Evans & Sutherland Computer Corp., Salt Lake City, Utah