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Photo Engineer
01-08-2008, 05:30 PM
Ok, this might interest you but many graded enlarging papers today are ortho sensitive. This was a surprise to me too. The reason stained negatives give oddball contrast on VC papers is obvious, but the results on a graded paper are kinda unknown I guess.

If you wish to test your paper for green and blue sensitivity, expose them through a wratten 98, 99 and 70 and this will give you the relative speeds to B/G/R light. Of course Ilford MGIV would be your reference. You may be surprised to see the results. I was.

PE

JBrunner
01-08-2008, 05:48 PM
PE,
You may be interested to know that one of the reasons I favor PMK is because of the effect the green stain seems to have when split contrast printing. The PMK negs seem to split the hard and soft exposures more effectivly than negatives developed by other means.

J

Photo Engineer
01-08-2008, 05:55 PM
Well, I can't make a VC Azo yet, but I have ideas how. I have read about what you describe though. I'm referring though to many enlarging papers having green sensitivity even though they are not VC papers. This is probably one way they are picking up some speed.

PE

Kirk Keyes
01-08-2008, 05:57 PM
PE - a green sensitive paper that is graded, i.e. not multicontrast, will respond just fine to a stained negative. The paper can not and will not react any differently from a plain old un-stained negative. Follow the link on this page on my web site and you will see a comparison of the stain on a couple films processed in two staining developers, one in PMK and the other in Pyrocat-HD. The films are TXT320 and FP4+, but I don't think there is a significant difference in that. The films were bleached and the silver was removed, leaving only the stain behind and then the films were scanned in a spectrophotometer.

There are two lines plotted for each film, one from a section of film base with only fog, and the other line is from a portion of the film with density - they were exposed with a Stouffer step wedge and Step 1 or 2 is used for these.

Keep in mind that the plots are only intended to give a general idea of the stain density - the areas of film used were not matched in density nor was the development of each film matched for gamma or CI. They just happened to be the sheets I grabbed to do the test with...

Anyway, you can see the Pyrocat really doesn't have much absorbance in the green or even the blue, especially when compared to the PMK neg. I think there will be minimal difference in exposure with a Pyrocat neg using your green-sensitive paper when compared to a blue-sensitive one, except it may be a bit quicker as it transmits a bit more light in the green. The PMK neg will probably print noticeably faster with the green sensitive paper as it has much less absorbance in the green so it should let more light through.

I think this is what you are trying to get at, right?

Kirk Keyes
01-08-2008, 05:59 PM
http://keyesphoto.com/KDKtech%20-%20Spectral%20Scans%20of%20Pyro%20Developed%20Film .html

Forgot to add the link!

Photo Engineer
01-08-2008, 06:24 PM
Yes, Kirk, that seems to be what I was asking. But, in that case there may be no advantage to having green sensitivity at all except for more green speed. I can make it faster without green speed. So it might just increase the effort and expense with no yield of any benefit in imaging, as the speed alone is easy to do.

PE

juan
01-09-2008, 08:42 AM
The thing that I so loved about Azo was the 3-D effect one could get. In the past, PE, you've said that was a paper or base effect, not an emulsion effect. Is that still the case?
juan

Kirk Keyes
01-09-2008, 10:08 AM
Yes, Kirk, that seems to be what I was asking. But, in that case there may be no advantage to having green sensitivity at all except for more green speed. I can make it faster without green speed. So it might just increase the effort and expense with no yield of any benefit in imaging, as the speed alone is easy to do.

PE

Yeah, that's kind of the way I see it. A neat thing to be able to do, but maybe not that useful?

gbenaim
01-09-2008, 04:46 PM
One application noone has mentioned is enlargements, if it can be made fast enough.

Curt
01-09-2008, 07:06 PM
How soon can I order a couple of hundred sheets of 11x14?

Curt

Photo Engineer
01-10-2008, 06:44 PM
Juan;

Others would have to evaluate the effect on my paper to see if it is, in their opinion, 3D. IDK. I'm not an expert in Azo printing, merely Azo making (if you will - :D ).

It cannot, at this time, be made fast enough for enlarging, but I do have a Kodabromide type paper that is about the same speed as Ilford MGIV paper.

PE

papermaker
01-11-2008, 06:29 PM
The thing that I so loved about Azo was the 3-D effect one could get. In the past, PE, you've said that was a paper or base effect, not an emulsion effect. Is that still the case?
juan

Juan,

If by "3-D effect" you are referring to the surface texture, like fine grain,silk, etc., then yes, this was a result of the paper support the emulsion was coated on. There were several different textures available on Azo papers. However, the textures were the same as in other product lines and often the same paper would be used in more than one product line.

Tom Hoskinson
01-11-2008, 07:04 PM
Juan,

If by "3-D effect" you are referring to the surface texture, like fine grain,silk, etc., then yes, this was a result of the paper support the emulsion was coated on. There were several different textures available on Azo papers. However, the textures were the same as in other product lines and often the same paper would be used in more than one product line.

As I write this, I am looking at an 8X10 glossy AZO contact print that displays the 3D effect. IMHO, the surface texture of this print is not a significant contributor to its 3D appearance. IMHO, tonality is an important factor.

papermaker
01-11-2008, 07:09 PM
If there is a 3-D effect, it does not come from the paper support.

Photo Engineer
01-11-2008, 07:10 PM
Tom;

You will have to judge that from what M&P re-create or what I'm able to do. Or, OTOH, convince Fuji to coat it on paper support and sell their product in the US. I pretty much know the formula, and can tweak it in miniscule grades, but whether it satisfies an afficionado in the field is another matter.

PE

Tom Hoskinson
01-11-2008, 07:48 PM
If there is a 3-D effect, it does not come from the paper support.

I believe that the 3D effect displayed by this particular print has its source in the combination of the high spatial resolution of this AZO paper/emusion combination taken together with its ability to resolve micro-changes in contrast/tonality.

FYI, I am looking at an AZO print I own, made by Francesco Cicoli Abad. Francesco split developed the print in Agfa Neutol WA and Moersch Pyrocatechol, then Selenium toned it.

Photo Engineer
01-11-2008, 08:03 PM
I believe that the 3D effect displayed by this particular print has its source in the combination of the high spatial resolution of this AZO paper/emusion combination taken together with its ability to resolve micro-changes in contrast/tonality.

FYI, I am looking at an AZO print I own, made by Francesco Cicoli Abad. Francesco split developed the print in Agfa Neutol WA and Moersch Pyrocatechol, then Selenium toned it.

Tom;

FYI, the actual tone scale of grade 2 azo was rather compressed compared to some other contact and enlarging papers, so it is really difficult to explain what is going on. It may be physical and outside of H&D curves, or it may be just perception. IDK, but there are data to say both are true.

I cannot answer this, except to say that Azo was unremarkable in many ways.

PE

Tom Hoskinson
01-12-2008, 01:26 AM
Tom;

FYI, the actual tone scale of grade 2 azo was rather compressed compared to some other contact and enlarging papers, so it is really difficult to explain what is going on. It may be physical and outside of H&D curves, or it may be just perception. IDK, but there are data to say both are true.

I cannot answer this, except to say that Azo was unremarkable in many ways.

PE

unremarkable in many ways - perhaps - , but in the hands of a photographic artist - beauty is most surely achievable.

As I write this, I am looking at Alex Hawley's Beautiful 8x10 contact print - "Barn Siding" - printed on Strathmore art paper coated by Ron Mowrey with his silver chloride contact printing formulation. This is a beautiful print and it is IMHO, very similar to AZO. Alex developed this print in Ansco-130 and Selenium toned it.

"Barn Siding" shows the "3 dimensional" light and shadow effects that I associate with AZO prints and PtPd prints made by master photographers/printers.

Photo Engineer
01-12-2008, 09:33 AM
Tom;

Thanks very much for the comments. I have been trying to duplicate Azo, but I was still not sure how well I had done. You have made me feel that I'm getting close.

The Strathmore was chosen for my original efforts due to ease of coating, cost and most importantly to me, the fact that it had a slight warm tone to it similar to a Kodak Ivory or Buff colored support.

PE

JBrunner
01-12-2008, 10:23 AM
IMHO the 3-D effect is something of an artifact of the contact printing process, when using a negative that has a high contrast, but good tonality in the highlights. Some of my contact prints on Varycon and Ilford MG display this effect, usually negs that I have shot and developed for N+1. The curve and Dmax of AZO no doubt contribute, when using that paper, or similar.