contact printinggreenspun.com : LUSENET : Large format photography : One Thread
I'm planning to try 8x10 contact printing using AZO and Amidol as described in monograph by Michael Smith. He suggests using a R-40 300 watt bulb. Other printers talk about using a 15 watt bulb. Is the AZO paper that slow? Appreciate any input. Thanks Lewis
-- Lewis Lauring (firstname.lastname@example.org), March 07, 2000
-- Nathan Congdon (email@example.com), March 07, 2000.
I think the paper speed is listed by Kodak as 8.
-- Mark Christopherson (firstname.lastname@example.org), March 07, 2000.
I am currently using a 150 watt bulb of the same design to allow longer printing times and therefore more time to dodge and burn. In older photo/darkroom books I have read descriptions of using smaller wattages still, like 15 & 25 watt bulbs - 10 inches or less from the paper. My bulb is about 4 feet from the paper. It wouldn't hurt to have a variety of wattages as well as a mechanism for moving the bulb closer and farther from the paper. Also, saafelight fog becomes considerably less of an issue.
-- Sean yates (email@example.com), March 08, 2000.
With Azo and Amidol, it isn't the Azo that's slow, it's the Amidol. If you develop Azo in a "normal" developer such as Dektol, your exposure times will be pretty normal even using an enlarger as your light source. If you develop in Amidol, you'll need a much stronger light. I've used a 250 watt bulb about two feet from the Azo paper and when developed in Ilford Universal developer I couldn't get a short enough exposure time to produce an image. Even at 3 seconds the paper turned completely black. I switched to using my enlarger head (Aristo 4500 VCL) without a lens, about 15 inches from the paper, and got exposure times of about 30 seconds using the Ilford developer. Though I haven't tried it yet, a friend says that with Amidol and a light similar to my 250 watt light, exposures of about a minute are required.
-- Brian Ellis (firstname.lastname@example.org), March 15, 2000.
Brian I don't think the Amidol effects the exposure time. I have been using Dektol to develop my Azo and had printing times of 8 -15 seconds with a standard household 300 watt reflector flood. So I switched the bulb to a 150 watt at about 4 feet and got a more manageable 20 - 30 second exposure.
Last weekend I attended a workshop with Paula Chamlee and Michael A. Smith. Michael printed from one of my negatives with his set-up and developed it in Amidol. The exposure time was 10 seconds. I had printed the same negative in my home darkroom with the old set-up for 12 seconds.
-- Sean yates (email@example.com), March 15, 2000.
I've read with interest responses from Brian and Sean. I have now printed the same series of negatives with Photographer's Formulary weston's formula amidol, Dektol 1:3, and Agfa multicontrast paper developer, and tend to agree with Brian. The printing times are long for amidol and relatively short for dektol and agfa. The Amidol seems more pleasing to my eye with a little warmer image than the dektol or agfa. There is also more control with the amidol. I have varied my light source to include a 300 watt r-40 as well as 120 and 85 watt,have also varied distances from light to table 3 to 4 feet. Next question? What are some other sources for amidol, I mean the bulk chemicals to make the working formula? At about $10 per quart, the Formulary kit is too expensive for me. Has any one had experiences with toning Azo paper,other than in Selenium? How can I warm up the image some more?
-- Lewis Lauring (firstname.lastname@example.org), March 19, 2000.
The cheapest place I've found for amidol is TCI in Oregon http://www.tciamerica.com/catalog/catalog.htm Much cheaper than the Formulary, but it looks like you need to buy a pound. You might double check the purity, if thats an issue. The cheaper amidol that TCI sells is 97% pure and 150/lb, you'll pay nearly double for 98% pure. I cant imagine that 1% makes a big diff, and its probably what formulary sells.
Theres a place in Canada, I think Fotochem, and their prices arent bad. You might look for other Canadian suppliers, with the exchange what it is you might find some even cheaper (hate to use that word cuz it aint cheap) than TCI.
Now to get it really cheap would require a group of photographers to get together and go in on a 50 lb package. I havent seen anyone who sells that large a package (estimated price-$5000??), but it would probably bring the price per pound down into the expensive range rather than the outrageously ridiculously expensive range that its in now- if you could find it and find 20-30 others to go in on it.
-- Wayne (email@example.com), March 19, 2000.