Obsidian Aqua, catechol staining developer

[onnect17]

I buy most of the chemicals at Artcraft Chemicals. How much did you pay for 250g of catechol from Poland?

[Regular Rod]

I paid €70.00 for 1 kilo in 2012 so I was wrong to imagine there was a BIG saving as that works out at $23.71 per 250g. My apologies.

RR

[onnect17]

No apologies needed. It's always good to discuss about sources and cost for chemicals.

[Michael Kadillak]

Have never mixed Pyrocat HD with anything but water. Very simple and inexpensive as well.

If the difference is not anything that I can actually see in the final prints - why change?

Add in that Sandy King is a good guy and I'll stick with it.

Times two on all counts. Sandy is and has always been a distinguished dignitary academically and within the photographic community. They don't come any better.

[Andrew O'Neill]

Ken, I dry-mount scanned the negatives with a V750. Full negatives at 600dpi. 48bit colour. For the smaller samples I scanned in at 4800dpi. I kept the green channel and eliminated red and blue channels in PS. No sharpening.

Personally, I like pyrocat-hd and OA and will use them both.

[C_Remington]

If it's as good as the name you picked for it, I'll have to try it! Maybe you should be
in marketing!

Indeed. Marketing.

[Regular Rod]

Indeed. Marketing.

I don't understand this attempt at cynicism. No one is being forced to even read about OBSIDIAN AQUA let alone make it and use it. An attractive aspect of OBSIDIAN AQUA is that it is being used purely on its merits. There is no marketing, nothing is for sale. The formula has been given by its inventor, free, gratis and for nowt, to us all. It is published in the public domain for all to see, consider and, if so minded, to make and use. It is a very useful developer.

RR

[Taija71A]

Indeed. Marketing.

I don't understand this attempt at cynicism. No one is being forced to even read about OBSIDIAN AQUA let alone make it and use it. An attractive aspect of OBSIDIAN AQUA is that it is being used purely on its merits. There is no marketing, nothing is for sale. The formula has been given by its inventor, free, gratis and for nowt, to us all. It is published in the public domain for all to see, consider and, if so minded, to make and use. It is a very useful developer. RR

____

Rod, agreed in full 110%
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I think that some people are unable to accept, that Obsidian Aqua and/or the latest version of Hypercat are just as good... If not Perhaps? even slightly better (*On some individual counts) -- Than Pyrocat-HD.
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Best Regards,

-Tim.
________

[catalinajack]

For those of you who prefer to use rotary processing (Jobo) and are okay with a slight reduction to box speed, what length of time at what temperature do you for specific films? I use only Delta 100 and T-max 400 (4 x 5). And aside from the loss of box speed, are the results any different than processing semi-stand?

[onnect17]

The oxidation of the developer is directly linked to the agitation which depends of the speed and design of the tanks in the Jobos. Also, the amount and/or concentration of developer solution needs to be considered, so allow me to suggest using 2:2:100 instead of the regular 1:1:100 and start your tests on the 5 min mark.