I used a different developer but...Chlorhydroquinone is a less well know, perhaps old fashioned developing agent (and a relative of hydroquinone). It primary use is a in warmtone developer such as Defender D-58: I quote from a post made by Randy, another very interesting thread from him on (there was a url link here which no longer exists)
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Here is the formula from the Photo-Lab-Index 1949 version
Defender 58-D
Water 750ml
Sodium Sulfite 16.0grams
Chlor-hydroquinone 4.0grams
Sodium Carbonate 16.0Grams
Potassium Bromide 0.6grams
Water to make 1Liter
Develop for at least 4 minutes. With more exposure and less time in the developer tones will be browner but some deepness in the shadows will be sacrificed.
Chlor-hydroquinone stays active even down into the 50s°F range. Much lower then Hydroquinone.
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As seen in the link: C-HQ has the ability to develop fairly heavily fogged B&W paper fog free with clear whites. I had some fogged Kentmere Kentona I tried it: works like quite nice, but I have a few questions for those who are perhaps familiar with this developer:
I used a 4 min developing time at 20degC and obtain a nice warm tone image on the Kentmere paper (with a hint of pink/salmon), perhaps a bit weak in de max density. Is this to be expected ?
I diluted the D-58 1:1 with water per the recipe I found also elsewhere, but maybe I should not dilute ?
The next day I wanted to print a few images more, to find out that the developer has almost lost all it's strength. The developer is not keeping well once mixed ?
What colour does the solid chloro-hydroquinone have ? Mine is tan coloured (bought in 2002) and the resulting mixed developer is light brown coloured.
Best,
Cor
Hi CorThanks for the feedback, guys!
I guess I have to experiment a bit further, perhaps D-58 (or 58-D) is a weak developer by nature anyway; only one developing agent, the paper needs loads of exposure, and a long development time.
remains the question: is my C-HQ solid stock from 2002 perhaps oxidised since it has a tan colour as a solid and light brown in the D-58 ? According to the MSDS the colour of the solid should be beige, and mine is light brown/tan.
best,
Cor
Chloro-HQ was noted by EK as a developer of little extra value for the cost and difficulty making it. It was never commercialized and fell out of disfavor as other agents could do the same job or better.
PE
Chlorohydroquinone was also used in Crawley's FX-9 with diethyl-p-phenylenediamine sulfate. The developer was said to produce extra fine grain without an emulsion speed loss.
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