Obsidian Aqua, catechol staining developer

[Andrew O'Neill]

Jan, I haven't printed this negative. I exposed it EI 64, but after measuring with a densitometre, I probably could have exposed at 80.
Hi Luc, I get my chemicals from Nymoc in Toronto. Email John Burrows: nymoc@bellnet.ca

Ken, I marked the negative area that was enlarged. As you can see, it would have to be enlarged quite a bit before you can really see a difference.

[StoneNYC]

ALMOST bit the buklet to buy some Catechol while ordering some CD-3 from Artcraft, but in the end I decided I have so many B&W developers I should run through those first before going crazy on something new.

But it brought a question, since I've never used pyrocat HD or any other staining dev, as far as fine grain and pushing, I always use DD-X... So, how does it compare to DD-X?

[Andrew O'Neill]

For me, a pyrocat negative allows me to print the same negative in silver or alt processes (I've not printed an OA negative yet). High values seem to print softer tonally on VC papers than with a conventional developer. Staining developers are supposed to have smoother tones, less grain due to stain filling in the spaces between the grain. Most of my experience with conventional developers has been with Xtol, which I have heard, is similar to DD-X, no? If you want to try a staining developer, OA might be a good one to try, since it only requires three chemicals, and mixes quickly and easily.

Now I need to focus on this hockey game. Been multi-tasking most of the day between this thread, making a carbon print, and watching the Canucks and Sharks game.

[rcmartins]

Andrew,
Could the differences between the two films stem from a slightly different agitation during development? I am asking because I honestly don't know. I am not implying anything with the question.
raul

[Ken Lee]

Ken, I marked the negative area that was enlarged. As you can see, it would have to be enlarged quite a bit before you can really see a difference.

Presuming that the film is 4x5, and sizing the image to 3.75 inches tall, the detail section is around 3/64 of an inch. I'm guessing that the detail section is around 1/20 inch tall on the negative. To see the detail section at 1 inch tall, we'd need an enlargement factor of 20 x.

[Andrew O'Neill]

raul, agitation was exactly the same.

[dsphotog]

What fixer would be best with OA?

[Regular Rod]

I use Ilford Rapid Fixer after a 20 deg. C stop bath of water.

RR

[Andrew O'Neill]

I use Ilford Rapid Fixer after a 20 deg. C stop bath of water.

I use the same fixer.

[StoneNYC]

Please correct me if I'm wrong, because I really don't know that much about the chemistry and of things, but isn't the fixture that is used more dependent on the type of film that you're using then the developer itself?