PN 55 Pod Chemical Analysis

[dwross]

Hi Mustafa,
Nice to hear from you again. You always spark great discussions and you've gotten some really sound advice here already.

This one has me a bit confused, though. There are two reasons to pursue historical information: 1) as a 'purist' whose primary interest is basically in technical archeology - facts for the sake of fact alone, and 2) as a creator of art who yearns for the look of an extinct product. You can be both, of course, but the direction you start your investigations is very much determined by which is more important to you. You say that your friend has tried pan x with a monobath, so that hints that he may be looking from an artist's viewpoint.

Kirk is spot-on about the costs involved if you hire an outside lab. Ouch! Really. Keith is smart to point out the pitfalls of comparing current emulsions with old, even if they carry the same name. If art is the primary goal (and, of course, pure science can always follow later), perhaps you and/or your friend should learn plain, old-fashioned emulsion making. It might seem like a backdoor approach, but it is after all how it all started. Reverse 'reserve engineering' if you will.

Best,
d

[dwross]

I see I should have taken a peek at what was posted while I typed. There is indeed a third reason - the entrepreneur. If your friend is serious, I evenly more strongly advise first learning a bit about the basics of emulsions. It will serve him well in the long run.

[Mustafa Umut Sarac]

I think We are sniffing the air like an old grey wolf to find a product who lost his way

[BobCrowley]

I have the 55 reagent or something very close to that reasonably well analyzed. The Haist book is also an excellent monobath treatise which does touch upon the reagent without being specific. There is no specific 55 related patent that I know of after a fairly intense review. At least one suitable off-the-shelf emulsion has been identified that could be used with the reagent - but - we do not have a handle on the DTR kinetics yet, which are determined by, among other things, the receiver sheet.

That's the part where I could use some help.

Much more on http://new55project.blogspot.com

[Photo Engineer]

The two main ingredients that I remember are KOH and Carboxy Methyl Cellulose.

PE

[Kirk Keyes]

The two main ingredients that I remember are KOH and Carboxy Methyl Cellulose.

Neither of which would show it in a gas chromatographic analysis.

[Photo Engineer]

Correct Kirk. It would take a wet chemical analysis for organics and inorganics to really do the job right!

PE

[BobCrowley]

Yes KOH is fine and you can use LiOH - either one with a pH of 11 when all is mixed. Cellulose thickener is to regulate spread rate and thickness. Other materials such as silica have and can be used.


If you are familiar with Haist you will recognize this:


from the 55 pod MSDS

POTASSIUM HYDROXIDE 1-5 001310-58-3
LITHIUM HYDROXIDE MONOHYDRATE 1-5 001310-65-2
T-BUTYLHYDROQUINONE 1-5 001948-33-0
SODIUM SULFITE ANHYDROUS 1-5 007757-83-7
SODIUM THIOSULFATE PENTAHYDRATE 5-10 010102-17-7

I am up to my ears in what are essentially monobaths. But the above used alone, don't expect a good cleared negative. The receiver sheet construction, nucleating properties and absorption of dissolved silver appear to be important, and while there are many patents and descriptions of the receiver sheet, none are specific (or say they are) to 55.

Please someone out there must have some knowledge of the production and preparation of the older receiver paper, the stuff that needs coating. If you do, I would gladly compensate expenses as this part of our project is proving costly, time consuming, and tying up resources as we cast about.

The rest is straightforward. If the economics are right, and we follow through (after knowing receivers) I am quite sure we will have a high quality 4X5 and maybe 8X10 field processable negative system with some kind of positive as a remnant, at least. It can be made as complicated as we like, but this isn't actually very hard as long as we remember we are not trying to make 55.

Thanks

[Photo Engineer]

Bob;

It needs a thickener to make it spread properly. IDK how much, but a little bit of CMC goes a long way.

PE

[jnanian]

P.S. also note that the current (aerial) panatomic-x is likely not the same thing as what we have in type 55. All I have said (and others too, if I remember correctly), is that there appears to be a close resemblance. But the aerial stuff probably differs in terms of spectral sensitivity.... and that may have implications for how it is best developed. I'd expect aerial to be considerably more red sensitive.

aero film
had red sensitivity
to cut through haze ..
pan x wasn't quite like that ...
but aero x from mr foto1 is pretty cheap


john