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Photo Engineer
04-19-2007, 10:42 AM
After due deliberation, I have figured out a way to make a variable contrast contact paper similar to grade 2 and 3 Azo.

My question is this.... Would there be any use for it?

It would use UV and blue light to get the 2 contrast grades.

PE

David A. Goldfarb
04-19-2007, 10:51 AM
It sounds like more trouble than it's worth if the range is from grade 2-3. Make it from grades 1-4, and then it starts to sound more interesting.

On the other hand, if you're coating your own anyway in small quantities, it seems that one could always just coat to the contrast one needs.

jgjbowen
04-19-2007, 01:33 PM
PE,

I want to encourage your work in this area....But, as an Azo user, I have both a blue, Zone VI, cold light and a UV "The Cold One" Azo head. If I had to change heads back and forth in order to vary the contrast, I would probably shoot myself or turn to platinum printing.

How do we practically change light sources from UV to blue?

Most Azo users would likely use grade 3 and an waterbath to vary the contrast from grade 2 to grade 3. We as a group would probably much prefer a straight grade 3 and a grade 4.

Scott Peters
04-19-2007, 01:40 PM
Not necessary....just grade 3 with water bath is acceptable to get down to lower grades. Grade 4 would be nice to have around for those rare occassions though....

Changing lights seems like more trouble than its worth. I wonder how the azo testing is going......

Photo Engineer
04-19-2007, 01:52 PM
The light could be a mixture of UV and visible (Blue) with a UV filter that moves in and out of the beam and a yellow filter to vary the UV content vs Blue content.

With some thought, I think I could make a grade 1 - 4 but it would be a LOT harder, so you can comment on that as well. I have made both extremes of paper so it is not impossible.

As for Azo, that is a Kodak trademark so testing of Azo is not what we should be asking. Lodima is a trademark of M&P and I am calling mine an "Azo Like" paper. AFAIK, you have to look to M&P or any of their authorized test individuals for comment. Last I heard, their tests were going poorly as read from their web site.

From my reading of Michaels own account, I don't think it is possible for them to make a usable Azo type paper from their current formula. I've commented on that before here on APUG. I do wish them well though. However, I have no idea of the capability of the engineers they have hired to do this job.

PE

rmazzullo
04-19-2007, 02:24 PM
Hello all,

You can get UV LEDs and Blue LEDs very cheaply nowadays, and can create rows or banks of each in the same "lamp head", and switch the rows on or off as needed, to vary the mix of UV and Blue. (There are even different shades of blue, depending on where you get them from. Solid state, and instant on / off. The only caveat is that you cannot look into the UV light.

It might be possible to 'dim' one side or the other as needed, but there is some extra circuitry (not hard to build) that might be required to do this.

Thanks,

Bob

Scott Peters
04-19-2007, 04:34 PM
Ok, grade three then for A_O like paper...hopefully we will hear about the 'new A_O / Lodima testing soon.

Shawn Dougherty
04-19-2007, 04:38 PM
Speak for yourself man, grade 2 is a must. Shawn

skillian
04-19-2007, 05:55 PM
What difference does any of this make unless this paper can be commercially produced? Maybe it's easier to hand-coat than it sounds, but all this talk about silver chloride papers that I can't have is like giving me a case of "Azo blue balls".

Photo Engineer
04-19-2007, 07:56 PM
Scott;

Try imagining it being commercially produced and then re-post.

Thanks.

PE

skillian
04-19-2007, 08:19 PM
I've been imaging it since Azo was discontinued, but Lodima isn't here yet and the last time I read one of your threads, you said you weren't interested in making anyting commercially available. Did I miss something since then?

Photo Engineer
04-19-2007, 08:29 PM
Scott;

You missed nothing. I'm merely gathering information before doing experiments. I'm trying to determine the utility of a material, and I cannot do it unless I get answers to the question.

As for Lodima, I am sorry about the situation, but I can say that the wait will probably be a long one. It has already been what? About 2 years? I wish you the best.

PE

Jim Fitzgerald
04-19-2007, 09:32 PM
Ron, I for one would be very interrested in it!

Jim

Scott Peters
04-19-2007, 09:48 PM
Well, if it is commercially produced then I would be interested and could work around the "lighting" to get the variable grades. Can you shed some light on the commercially produced aspect? what exactly do you mean? thanks.

juan
04-20-2007, 07:35 AM
I would be interested in it, whether hand coated or commercially available.
juan

rmazzullo
04-20-2007, 08:06 AM
I guess this almost goes without saying, but I am interested, too.

Bob M.

Peter Schrager
04-20-2007, 08:18 AM
Ron-I can't find the recipes here on APUG you mentioned....where do I look??
Peter

ilya1963
04-20-2007, 08:33 AM
Azo is veriable contrast
I could practicly go from grade two to grade four with the same sheet of paper developed in Amidol , it litteraly has no end ...

Just my experience ...

ILYA

Photo Engineer
04-20-2007, 09:14 AM
Well, if it is commercially produced then I would be interested and could work around the "lighting" to get the variable grades. Can you shed some light on the commercially produced aspect? what exactly do you mean? thanks.


Scott;

I've never discussed commercially producing any of my emulsions here on APUG. I am not currently engaged in doing work towards that. I may someday, but that is not for me to determine. I don't have any facilities for commercial production, nor do I plan on buying or building any.

PE

Photo Engineer
04-20-2007, 09:16 AM
Ron-I can't find the recipes here on APUG you mentioned....where do I look??
Peter

Peter, the formulas published here are in this forum in another thread. You actually made this formula in the Workshop and took pictures with it, albeit with some 'improvements'.

Ron