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A real formula


I'm very interested, and if I ever scare up an IR dye, I'll help you get started on that.

NOTE: To Simon Galley.... There is a market for this stuff. EK won't believe me, but here are 2 customers already. I'm sure that there are more.

PE
 
xenocyanine is an IR dye

Neocyanine is available from Cole-Parmer $88.50 for 1/2 gram.
3,3'-Diethyloxatricarbocyanine iodide is 107.25 for 1/2 gram
 
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so is 3,3'-Diethylthiatricarbocyanine iodide, available from Sigma-Aldrich for $56.00 per 1 gram bottle.
 
Try H. W. Sands Corporation in Florida. They worked with EK. Also, you might try Honeywell in Germany.

But, I can't tell you everything, now, can I? Oh, I already have! ~grin~

Actually, I have Paul Gilman here as a resource to help me with dyes, and I'm not ready for IR dyes. I'm still back working on Ortho.

Thanks for the additional information.

PE
 
Actually, it was Rockland Colloid that informed me about tricarbocyanine dyes. Both their Ag-plus and Liquid light products will accept this dye for IR sensitization, IF anyone wants to try it out. Mr. Ryuji (who posts on this forum) put me on the path toward IR dyes. I know nothing, and have not tried any.
 
Oh? Liquid light accepting IR dyes? That's exciting ...

[gets more bad ideas]

too bad this is all so expensive :-((
 
I'm not sure that this will work very well, as the Liquid Light is already sensitized in the ortho region. Therefore, you will have Blue, Green and IR sensitivity if it works. It will 'kick' some of the dyes off the grain, or if not, it may decrease contrast by acting as an antifoggant or restrainer.

In any event, you will have to work in total darkness.

PE
 

That's not surprising. I've used that dye with bromide emulsions of various iodide content and structures and it works pretty well.

It seems that there is enough interest in IR sensitizing existing emulsions. I may consider making a page on this topic on my site when I have time to put the act together...

If you shoot 4x5 size, one thing you can do to make your life easier is to use hanger and tank to dye the film. If you make 4x5 plates you can do the same. Or you can make use of Fred Picker slosher type apparatus.
 
'That's not surprising.'

That I know nothing, or that it might work?



You'd most likely be right either way...

I'm going to try experimenting with these dyes when I can, but don't ever think I'm speaking from experience, because obviously I'm not. I do not claim and have never claimed to really know anything about this subject. I'm just passing on what people who (claime) they do know what they are talking about have said to me...
 
This is all _very_ intriguing - just wish I understood it! I'm new to all this and having just got my hands on an old (Wallace Heaton) 9x12 plate camera and plate holders, I was considering getting some glass cut to size by a local glazer and trying out the dry plate process on http://www.alternativephotography.com/process_dryplate.html . Has anyone on here tried this particular formula and how has it worked? I'm not sure where to get the Liquid Light that is mentioned on several forums, but in the UK I can get Adolux Liquid Emulsion - does anyone know if this is a suitable alternative?

What a fabulous site this is! I'm off to become a subscriber because we should all be supporting this sort of stuff

Cheers,
David.
 

SILVERPRINT London, PARTNER company of the LABOR PARTNER, located in Geesthacht/Germany, manufactures high-quality liquid photo emulsions for 25 years. These are offered up-to-date, under the brand name ROLLEI film. For now 25 years (founded in 1972) this assortment consists of PHOTO GELATINE Photopur, the identical gelatine, with which also the photo-sensitive emulsions are produced. This assortment was demonstrated some years ago, particularly in the USA, by British instructors at many academies. The assortment consists of DEVELOPER HARDENER ADDITIVES, an hardener solution, which is added to the DEVELOPER in small quantities directly. PHOTO EMULSION LPE210/new: ROLLEI RBM23, this is a pure bromide silver type, that proves the gradation HARD. The usually-sold PHOTO EMULSION LPE310/new: ROLLEI RBM33, the first industrially produced variable contrast chloro-bromide emulsion world-wide. In more traditionally Du Pont tradition. Also, for lith techniques suitable! The product range is supplemented by high energy developer, citro stopper, and ph-neutrally fixer. One can download the BLACK MAGIC guidance under www.mahn.net. It is admitted, this would have to be modernized, nevertheless, likewise exists for 25 years.
Who does not have time or desire to set the photo-sensitive B&W emulsion that can be ordered over Freestyle L.A.; Silverprint London; or directly from the manufacturer that satisfactorily worked, and world-wide admitted BLACK MAGIC B&W PHOTO EMULSION.
 
This emulsion, when sensitized properly and with other addenda and treatment is similar to the Ortho 40 speed emulsion that I posted elsewhere.

It is very sharp and very grainy. I have another ISO 3 - 6 emulsion that is only blue senstitive, but is much less grainy. I have yet to do much testing to see what kind of overall results can be obtained, particulary if I try to maximize the speed.

PE
 
Hi PE,

Thanks for your reply. I guess I was on the wrong track.

I am interested in the ISO 3 - 6 blue sensitive emulsion. If you get a chance to post the formula I would be very greatful.

Thanks,
Emulsion.
 
I'll try to get to it in a few weeks. Sorry, but my shcedule is getting tight right now. I will not forget.

PE
 
David,

you can use ADOLUX just like any other liquid emulsion for your first experiments in glass plate coatings. Basically the products out don´t differ much. But they are not really intended for the use in cameras. The liquid emulsions on the market today are used to make positive prints of already existing negatives and are sensitized up to about 560nm.
This means they are orthochromatic (blind for red light) in order to be used under a red safelight and will reproduce anything red as black in the positive.
Also they are rather slow and need long exposure times.
The other problem is to get the emulsion to stick to the glass evenly.
In this matter ADOLUX will not differ much from other emulsions but you need to sub your glass plates first. Recipes for such a preparation coating should be available on the site you mentioned, else Photo Engineer can probably shake a formulary for a subbing layer right out his sleeve. I could look something up for you otherwise.

Cheers from Berlin,

Mirko
 
Mirko;

Good comments.

A subbing layer is not normally needed, but one goes like this.

10% gelatin 100 grams
4 ml 5% chrome alum stock solution (stock is 10% chrome alum)
5 ml Everclear (95% ethyl alcohol)
1 drop 10% thymol in iso-propyl alcohol.

This should give a good subbing layer for you coated using normal plate methods.

If it is too thick, just dilute with distilled water in steps until the desired viscosity is reached.

PE
 
If one could get they're grubby little hands on Gold Chloride, (there is some of questionable origin on Ebay) and I understand, from a wiki article that sodium hypo and sodium thiosulphate are the same chemical, what concentrations of these would you use of these. Since the formula calls for about .77 Mol of silver, and I read in another post that sensitizers should be 1 - 10 mg per Mol of silver, do we use (assuming the high end of that scale) about 4 mg of AuCl and 4mg of Na-Hypo (pardon the chemical contraction) or 7.7 mg of each?

Also, I have seen other recipes that call for potassium Dichromate as a sensitizing agent. (unblinking eye.com) To my knowledge this only hardens gelatin when exposed to UV, which I would think help contrast, not increase sensitivity, and since it takes so long for the UV to harden the gelatin w/ K2Cr2O7, I dont seehow it would be of much use.

Lastly Does the hypo and AuCl sensitize down to red, or just into green?

THanks.
 
Silver halide is sensitized by adding thiosulfate at 1 - 100 grams / mole of silver present. Unfortunately, this level is based on grain size (surface area actually) and therefore unless you have electron micrographs you have to determine it by trial and error.

Gold is used a 1 part of gold salt / 3 parts of thiosulfate.

Don't use Dichromate.

PE
 
Thanks-

Just realized that the thiosulphate and and AuCl is for not for spectral sensitization - sorry for the stupid question.
 
totalamateur said:
If one could get they're grubby little hands on Gold Chloride, (there is some of questionable origin on Ebay)
Click to expand...

Go back to eBay, and buy from CJ Chemical or Salt Lake Metals. I've bought gold chloride and silver nitrate from both and they deleiver good product.

Or, try Photographers Formulary.

It's not so hard...
 
Hi,
Stay away from Pro-Blenders L.L.C.on Ebay. Their silver nitrate will be cloudy in distilled water. When ammonium hydroxide is added it will be clear, but pink.
Bill
 
Pink - that's pretty. I think that means there's manganese (pink at first, but it should turn brown on standing) or cobalt (was it blue for a little and then turned pink?).

The silver nitrate I bought from Salt Lake Metals was water clear with dissolved in water, and it turned a very, very pale blue when complexed with ammonium hydroxide. Probably a bit of copper... which PE will tell us is a no-no... ACS and AR grade are allowed 2 ppm copper in silver nitrate.

I suspect there was a bit more in the SLM silver nitrate I had, but I' guessing it was not much, as it was only blue with hydroxide and I only noticed the color when I poured it into a container so that it was more than a couple inches deep.
 
30 grams gelatin?

Hi PE,
I tried to make this formula, the full batch,not scaled down.
Upon chilling to 33 degrees F, the batch was very soft, realy too soft for noodling. I used Formulary gelatin,and formulary Br and I. The only suspect component was the silver nitrate, which I have mentioned above. But 30g of gelatin in 1.5 liters of water is only 2% gelatin. Then you call for an adjustment to 5-10% gelatin. Something is not right,is it me?
Regards,
Bill
 
You! Sorry Bill. I have mad this over and over and over and it works. You made it in class. Sorry.

PE
 
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