WD2H+ errata

Any errors or omissions you come across in the Darkroom Cookbook.
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michael r
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Joined: Sun Apr 03, 2016 6:25 am

WD2H+ errata

Post by michael r » Mon May 02, 2016 11:28 am

Steve,



Just finished reading through the new 4th edition! Congrats.



It looks like WD2H+ is wrong again. The bisulfite is there, but now it's missing the pyro. In the preface, the reference to the WD2H+ error in the 3rd edition indicates sodium metaborate was missing (obviously it was bisulfite which was missing).



Congrats again on the new edition. Although I'm an "analog" worker I'm looking forward to reading the new section on digital negatives.



Best,

Michael

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sanchell
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WD2H+ errata

Post by sanchell » Mon May 02, 2016 1:28 pm

I can't f**king believe it (it's okay to use blue words if they're referring to your own stupidity).



One of the motivations for publishing the 4th edition was to rectify the error to John's WD2H+ formula in the 3rd edition. I appear to have overwritten pyrogallol, 60.0 grams when I inserted the sodium bisulfite.



Please don't anyone tell John until I've had time to shoot myself.



In the meantime, here is the corrected formula.



Here is the correct Solution A for WDH2+



WD2H+ (2003)

(John Wimberley)



SOLUTION A

Distilled water, 750.0 ml

*Benzotriazole, 0.2 g

Metol, 6.0 g

Sodium Bisulfite, 20.0g

Pyrogallol, 60.0 g

EDTA tetrasodium salt, 5.0 g

Distilled water to make 1.0 liter



SOLUTION B

Distilled water, 750.0 ml

Sodium carbonate, monohydrate, 110.0 g

Distilled water to make 1.0 liter



*For more accurate measurement, prepare a 1% solution by dissolving 1.0 gram of Benzotriazole in 100.0 ml of distilled water. Use 20.0 ml in place of 0.2 grams dry chemical.



Working Dilution for Normal and Reduced Contrast



Distilled water, 1600.0 ml

Stock Solution A, 25.0 ml

Stock Solution B, 25.0 ml



-2 EI 32 Develop 7 minutes

N EI 64 Develop 9.5 minutes



Working Dilution for Increased Contrast

Distilled water, 1600.0 ml

Stock Solution A, 25.0 ml

Stock Solution B, 50.0 ml



+2 EI 84 Develop 6.5 minutes

+4 EI 100 Develop 12 minutes



Developing Times and ISO ratings are for Ilford FP4+, tray processed with continuous agitation at 68F/20C. These specifications should also apply with slight adjustment to other medium speed films. For slower films, the developing times will need to be reduced by about 10%. For faster films, developing times will need to be increased by about the same amount.
Do it in the Dark,



Steve Anchell

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