[MF3D.FORUM:237] Tech Pan reversal protocol

["David W. Kesner" <drdave@xxxxxxxxxx>]

Hello Joel and everyone,

> I'd be interested in your friends EI and process.

Here is Fritz's protocol for reverse processing Tech Pan:
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I posted my protocol for reverse processing onto photo3d last fall 
along with an offer to process a roll for anyone that wanted to try it 
to see.  It really isnt a diffucult protocol.  It does, however, require 
that you be very careful in your metering and timing of the first 
developer.  Here is my protocol:

Expose: EI 12

Solutions:
First Developer:  1:20 HC110 + 2g/L Sodium thiosulfate
Bleach: 9.5g Potasium Dichromate + 66g Sodium Bisulfate.  Total 
volume 1L
Clear Bath: 50g Sodium Sulfite. Total volume 1L
Second Developer: 1:10 HC110

Protocol:
First Developer	10 min
Wash			5 changes water
Bleach			3 min
Wash			until water comes out clear (>5 changes)
Clear Bath		2 min (max)
Wash			5 changes water
Expose			1 min each side to light
Second developer	5 min
Wash			5 changes water
Fix				3 min
Wash			5 changes water
Hypo Clear		1 min
Wash			10 min
Photoflo
Dry

The resultant slides have a dynamic range of about eight stops of 
exposure from Dmax to clear film base.  That level of contrast is 
about right for pictorial work with an "average" scene which will 
have in the neighborhood of five to six stops of illumination.  In high 
contrast situations, though, it probably wont be enough so be aware 
of the scene contrast.  

Because you are dealing with a transparency and also because of 
the high contrast nature of the film processed in this way,  it is 
important that you meter carefully and bracket important exposures. 

When I am shooting something that I think will be tricky, I bracket by 
1/3 stop for a stop each side of what the meter is telling me.  In 
general,  the tricky situations are those where I am trying to 
maintain a lot of highlight detail (for instance there is a white church 
building with lots of detail work near here that I shot once) and 
bracketing towards underexposure is what gives me the best 
slides.  In an "average" scene that approximates 18% gray,  
metering straight usually gives good results.

I hope that was what you were looking for.  Let me know if I can be 
of any further help.

Fritz M. Brown
brownf@xxxxxxxxxxxxxxxx
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That's all for now,

David W. Kesner
Boise, Idaho, USA
drdave@xxxxxxxxxx