Enlarging on Azo is now a reality

[Michael A. Smith]

Tonight Paula and I had the privilege of being the first, besides the inventor, Pat Brady, to test his new light source for enlarging on Azo paper.

Heretofore, Azo has been a paper for contact printing only. It is a slow paper and if one wanted to enlarge on this most beautiful of silver papers, the enlarging times were unduly long--easily getting to 15 minutes to one-half hour with a conventional enlarging head. A few years ago Durst came up with a 5000 Watt bulb so that one could enlarge onto Azo, but the cost is $6,000, I believe, and most folks would have to get their wiring upgraded to carry such a load.

Pat Brady's invention, by comparison, is a dream--no extra wiring, no hot lights, and short exposure times.

His invention is to use a set of four custom-made bulbs that put out light in the near-UV part of the spectrum. The four bulbs insure even coverage of the negatives. By using that part of the spectrum that Azo is most sensitive to, enlarging times are shortened considerably. Paula and I enlarged 4x5 and 2 1/4 negatives. Our exposures ranged from 30 seconds to two minutes and that was with our Super XX film which has a fairly high film base + fog density. With modern films, the exposure times should be less.

The housing for the light fits Beseler and Omega 4x5 enlargers and comes with its own voltage-regulated solid-state power supply. Each of the components is handsomely designed.

Although we will not be enlarging our LF negatives, because of this new light, at some point I look forward to reprinting all of the 35mm work I did during my first year as a photographer.

I understand that the light will be going to a few others to test during the next couple of weeks. After that, it will be at the LF Conference in Monterey in April and, I believe, it will be for sale at that time.

Paula and I think this is a great invention, and we hope it will help increase the sales of Azo as this slow paper will now be able to be used by those who only make enlargements. And that will help keep Azo in production.

 

[blansky]

Great, keep us posted. Any idea of price?



Michael MCBlane

 

[Sean]

Sounds like it could be just the thing to keep AZO kicking..

 

[Alex Hawley]

There have been several discussions about this over the last year on the Azo forum. As I recall, Michael related two very significant points. First, the expected price is about that of a cold light head. Based upon that expectd price range, Kodak executives looked favorably upon the invention as that could open a large market for Azo that wasn't there in recent years.

Many years ago, there was a large market for Azo as the snapshots printed by the local drugstore were done on contact printing machinery. Just do a search for "Azo" on e-bay and you will see these vintage prints for sale as memorabilia. As technology progressed, commercial contact printing went by the wayside, thus, so did the Azo market share. There are enlargers on the current market that can enlarge on Azo, but they are enormously expensive and have very powerful light sources. The light sources are powerful enough that standard residential wiring circuits are inadequate.

However, this invention has the promise of putting Azo back in market to anyone willing to spring the cost of a cold light head and runs off the standard household electrical outlet. A very significant achievement, to say the least.

 

[Michael A. Smith]

Not doing enlarging, I am under the impression that cold light heads sell for about $1,000. I understand that the light for enlarging on Azo will be a bit more--that it will sell for "between $1,500 and $2,000." My guess is that the final price will be somewhere near the middle, but that is only my guess.

 

[RAP]

Michael,

Thanks for the information. This presents some interesting thoughts on the future of fiber based, traditional papers. Has Kodak been consulted on this project? Does this indicate that AZO and other fiber based papers will be expanded upon, maybe produced by other companies? Where will this unit be sold?

Thanks!

 

[Michael A. Smith]

Kodak knows about this. It is one of the reasons they have kept Azo in production.

I doubt it will expand the marjket for other fiber-based papers, because the light is designed for contact printing papers only. And Azo is the only one of those in existence.

 

[Donald Miller]

According to the spectral sensitivity curves of conventional graded papers this unit may very well have more widespread application then just Azo.

 

[Annie]

This is exciting news, I wonder if this light source will have the capability to cross over into the Alt Process area. For someone such as myself it would be perfection to have an enlarger that is capable of utilizing 4x5 and smaller negatives on a great paper like Azo and printing Platinum from 4x5 and smaller negatives also. Is there any chance in the near future of testing for Alt Process applications?

 

[Donald Miller]

Annie,

I imagine that it would have the capability of exposing alt process if you have enough time to wait. Azo while slower then enlarging paper is still much faster then alt process from what alt process guys tell me.

Plate burners (such as the 26 1K) have a lot more UV output then this lamp.

 

[Jorge Oliveira]

From the sensivity curves of enlarging paper, a near UV light will be Ok with them.
While AZO is most sensitive to near UV, other papers are about flat from blue to near UV.
But this is for graded - VC may become grade 5.5!

Lenses may be trickier, some will block near UV.

Jorge O

 

[Donald Miller]

There are a number of factors that will impact on the operation of this light source. The first being that the greatest amount of experience to this point has been in contact printing of negatives with the "blue" portion of the visible light spectrum. This is what is exposing Azo when we use the reflector flood lamps. Thus negatives have been developed for this exposure spectrum.

The UV light source will change things for those who are using staining developers. The effects of this proportional stain will become more pronounced with certain developers when using the UV light source for exposure. The stain presents itself as greater density to UV transmission then it does to blue light transmission. In the negative density range that we normally use on Azo the effect of UV transmission can make a lot of difference insofar as the contrast on the print.

I believe that Michael Smith addressed this fact in one of his recent posts. Either here or on the Azo forum (I forget which).

The other thing that is going to become increasingly important is exposing and developing the negative more precisely. Excessive density will become the problem that it has long been for alt process printers. For that reason I think that to effectively use the potential of this light source film speed tests and camera negative density tests will be beneficial. To make welding goggle negatives will be a problem. I don't think that DBI will produce the results indicative of the potential that this light possesses.

Insofar as enlarging lenses. El Nikkor lenses will pass about a stop more UV light then comparable Schneider Componon and Rodenstock Rodagon lenses. This information comes from the inventor of this light source and also from Jens at Jensen Optical/Durst Pro. This is an important consideration as Jorge mentioned. There are probably another lens design or two that will work. I have heard of some really expensive quartz glass enlarging lenses that work too.

My first thought is that a negative developed to proper density range for grade two enlarging with pyrocat developer will probably be fairly near what is required for grade three Azo. However tests will need to be done to confirm this.

 

[Michael A. Smith]

Developing by Inspection can give you any kind of negatives you want. I do not understand your comments that it would not give you suitable neagtives for enlarging with this light onto Azo.

You can use DBI for any negatives--even 35mm roll film. Many of the old-time photographers did it that way.

 

[Jorge]

I beleive what Don is trying to say is that spped and developing tests will have to be more accurate for use with the UV light than with the regular azo/light bulb combination.

I agree with him, measuring UV vs transmitted light (blue channel) can mean as much as a stop and a half in absorbption, with the concurrent increase in b+f absorbtion.

If roll film is to be used to be enlarged onto azo, I feel accurate film speed and developing test will be of great value. While DBI is an useful tool, I dont think it is the best choice for negatives to be enlarged, specially with ABC.

 

[Donald Miller]

Jorge,

Thank you. That is what I was saying...perhaps too wordy in my explanation. I have used DBI and for the life of me I can not tell within .15 log units of density what the negative density is when examined with the green light. Perhaps I am not as adept as some of the practitioners of DBI and I will give that possibility. To be honest I can not tell within .15 log units of density in bright room light when I get up into the 1.85 area especially when considerations of proportional stain and different light sources enter the equation. I guess that I am not alone in that inability.

I think that we all want this light to produce a good result for purchasers and potential purchasers. I think that to do that the information that will enable those good results would be beneficial. This information may possibly indicate a departure from established methods. I gathered from the inventor a real awareness of density requirements for this light to work to it's full potential. I also heard his concern about over exposed and overdeveloped negatives. I fully concur with his thoughts on that matter.

 

[Jorge Oliveira]

At the time the semiconductor industry used UV lithography, there were lenses specially designed for it, all made of quartz.

If one is lucky enough to find one of these used, they are wonderful glass (for UV).

Jorge O

 

[Francesco]

It seems that enlarging on AZO and contact printing on AZO will require different types of negatives - i.e. for the former less dense (am I assuming correctly?). If this is indeed the case then a comparison of print quality between, for example, an enlargement onto 8x10 AZO and an AZO contact print of an 8x10 negative should result in one being superior to the other, at least in terms of tonal values, shadows, highlight separation etc. I find it unlikely that we shall find equivalence in quality between the two BUT I eagerly await the results.