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Photo Engineer
11-15-2006, 07:35 PM
Robo;

Yes, film emulsions are almost always bromoiodide emulsions from about 0.3% - 10% iodide and very large in grain, or from 0.2 - 5 microns in size.

Paper emulsions are usually bromide, chlorobromide and chloride (Azo). Grain size varies from about 0.1 micron to about 0.3 microns but there are exceptions, even with film emulsions.

Paper silver varies from about 500 mg/ meter square to about 5 g/meter square, and film varies from about 1 gram / metre square to about 20 or 30 grams per meter square (X-Ray is the highest).

I hope I got that right. At EK we used a mixed english metric system and I was converting from mg/ft square to mg/meter square and rounding.

PE

robopro
11-15-2006, 10:07 PM
OK, give me a day or two to digest that. In the meantime, how do you feel about multiple coatings on glass plates? I guess my question is, using a 'primitive' process with gelatin and hand coating on glass plates, would more than one coat really be of any noticable benefit? Right now I'm using albumen with 4 coats. I've never tried less or more -- just doing it because that's what the formula my friend gave me said to do, and it makes sense because you drain the excess from a different corner of the glass with each coat, so common sense tells you 4 coats would give you a more even total coating. If I switched to gelatin, would I see any real advantage to multiple coats?
I have to ask these stupid questions because I'm not a chemist and I need things explained to me in 'easy' terms. If you say mix 6 grams per 100 ml and add 4 ml of 1% solution, I understand that. When you start saying add 26% of 2% strength per 1.5 moles -- factoring in surface area and total volume...uhm, OK, what was that again?
I asked a question once about building a 'simple' lens for my camera and people went off on discussions about refraction coefficients and diopters. What the heck is a diopter? (Do you believe I can actually develop my own prints? I just follow the formulas and procedures that come with the materials -- I really have no idea how they work...) :-)

Photo Engineer
11-16-2006, 09:03 AM
A simple answer on glass plates then. With silver halide in gelatin, you only need one coat. Pour the emulsion onto the center of a warm plate and rock the plate until it is evenly coated. Let the excess drain evenly from each corner by tipping all for corners down in turn and then let dry. That should do it.

Do not coat unwashed emulsions on glass plates. They will not adhere. Use an aldehyde hardener for best hardening and adhesion. If you have problems, a gelatin under coat will help.

Make sure plates are dry and free from oil before coating.

A bit of Everclear (ethyl alcohol) and spreading agent will help the coating.

PE

robopro
11-16-2006, 04:19 PM
I think I'm about ready to give this a try. I have some experience coating glass with albumen -- which is probably thinner than gelatin. I think the rest I'm just gonna have to learn by doing. Time to start rounding up suppliers!
It'll be interesting to see how handmade gelatin negs compare to albumen.

This whole adventure began because I had this crazy idea about sensitizing albumen to infrared, but the speed is just too slow with ULF pinhole. I put the IR idea on the back burner for now, but I would like to be able to do 11X14 pinhole portraits, and looks like gelatin is the only way I'm going to get the necessary speed.
I'll keep the forum uprised of my progress, if anyone's interested...

dwross
11-16-2006, 04:30 PM
robopro:
re: if anyone's interested...

Very much so. Thank you for sharing your explorations.

Photo Engineer
11-16-2006, 05:46 PM
I think I'm about ready to give this a try. I have some experience coating glass with albumen -- which is probably thinner than gelatin. I think the rest I'm just gonna have to learn by doing. Time to start rounding up suppliers!
It'll be interesting to see how handmade gelatin negs compare to albumen.

This whole adventure began because I had this crazy idea about sensitizing albumen to infrared, but the speed is just too slow with ULF pinhole. I put the IR idea on the back burner for now, but I would like to be able to do 11X14 pinhole portraits, and looks like gelatin is the only way I'm going to get the necessary speed.
I'll keep the forum uprised of my progress, if anyone's interested...

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

25asa
11-16-2006, 09:29 PM
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

robopro
11-16-2006, 09:41 PM
so is 3,3'-Diethylthiatricarbocyanine iodide, available from Sigma-Aldrich for $56.00 per 1 gram bottle.

Photo Engineer
11-16-2006, 09:51 PM
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

robopro
11-16-2006, 10:09 PM
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.

htmlguru4242
11-17-2006, 08:15 AM
Oh? Liquid light accepting IR dyes? That's exciting ...

[gets more bad ideas]

too bad this is all so expensive :-((

Photo Engineer
11-17-2006, 11:32 AM
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

Ryuji
11-21-2006, 08:51 PM
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.

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.

robopro
11-23-2006, 08:16 PM
'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...

vickersdc
01-09-2007, 11:26 AM
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.

WRSchmalfuss
05-04-2007, 09:10 AM
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.;)

Emulsion
05-20-2007, 06:26 AM
It is great to see a formula and instructions.

PE would the formula that you posted provide very similar results to this Kodak film?

http://www.kodak.com/US/en/motion/products/lab/5302.shtml

Would it have similar resolving power?

Thanks,
Emulsion.

Photo Engineer
05-20-2007, 09:23 AM
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

Emulsion
05-20-2007, 04:37 PM
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.

Photo Engineer
05-20-2007, 04:41 PM
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