Liquid emulsions.. who is doing it?

[Ryuji]

Ron, if you argue that you have the knowledge in both public and secrecy of Kodak Research Lab, then why aren't you making better emulsions than anyone else? I have no secret info from Kodak or Fuji but I've been making good emulsions. I also shared my formula with several alt-photo people, some of which actually went to make their own batches, which worked well for them.

 

[Ryuji]

To me silver-gelatin is easier than many other processes and it is also very permanent in the way I process them. I have no other practical options than silver-gelatin because I enlarge 20 inch or larger, and the frequency of making larger prints is increasing.

I am not surprised that people would want to make their own emulsions. After all, I make carbon tissue and also print with a number of other alternative processes.

But why one would go to this much trouble for silver based photography? Why not use something more permanent like platinum or palladium?

I am assuming for this discussion artistic use of the emulsion as opposed to scientific experimentation and/or playful tinkering, which needs no further justification.

Sandy

 

[Photo Engineer]

Sandy, the coating thickness can be adjusted to very great values without bubbles. Part of the bubble problem stems from selecting the right surfactant, and removing bubbles by means of filtration before coating. This tends to aggregate the bubbles and remove them. Another part of the problem comes from entrained air. This is especially true when melting the solid gelatin in hot water. I have coated over 10 g/sq meter of gelatin and other ingredients (dry weight) both by hand and by machine. I have coated from water and a variety of organic solvents. I have never gone much over 10 g/sq meter though. Is that sufficient for your purposes? Of course, the wet weight of that level of gelatin was far higher than the dry weight quoted above.

Jim Bronwing, IIRC, is the one who has a coating apparatus for sale. He used it to coat thick layers for his matrix film formula.

Ryuji, as you know, I intend to eventually donate the formulas I come up with to the general public. I am trying to come up with easy to make formulas that do not use proprietary Kodak information, but which are simple enough for most people to make in their darkrooms. I am trying to compile a list of sources and resources to accompany the formulas so that a person can purchase a 'kit'.

I am trying to make as wide a range of paper grades as possible (1 - 4 hopefully), and one orthochromatic film formula with decent camera speed (ISO 25 or higher hopefully).

And, BTW, I intend to make no profit from this whatsoever.

I am aware of your work and neither intend nor imply any criticism of it. As I said above, "you do very good work yourself...". What I do imply is that there is a lot of art yet remaining in emulsion making and coating that is, simply put, "trade secrets of the companies involved". That is not fair game for discussion in this forum. It is also not fair game for me to use and then give away. I am working from and simplifying published formulas to come up with doable formulas by the hobbyist meeting the goals stated above.

I'm sorry if you feel otherwise about my efforts, my goals, or on my reluctance to speak.

PE

 

[sanking]

I have coated from water and a variety of organic solvents. I have never gone much over 10 g/sq meter though. Is that sufficient for your purposes? Of course, the wet weight of that level of gelatin was far higher than the dry weight quoted above.

PE

Ron,

10g/sq meter? I don't know how to relate that to my work. Could you explain the term as you mean it?

For carbon I make about a 10% solution of 250 Bloom gelatin, add pigment and other things, and coat with enough solution to produce a wet height of slightly less to slightly more than 1 mm.

About bubbles, it is not only the bubbles in the solution that matter. The greater problem is that warm pigmented gelatin, on contact with colder surfaces (as for example a leveler run over the top), produces a lot of bubbles. So your leveler, if you use one, must be above the temperature of the pigmented gelatin solution.

Sandy

 

[Ray Rogers]

Ron can answer this of course, but 10 g./ sq. meter would be using 100 ml of your 10% gel. sol. for every sq. meter you coat... what? 100 ml? 100 g. solution? I think.

It sounds like you might be using considerably more than this...

How many mls do you use to coat 1 square meter of.... tissue?

Ray

 

[Photo Engineer]

Sandy, I used a heated leveler in some cases. Just soaked it in hot water first and then dried it off. It was stainless steel.

I think at 1 mm you are probably at 100 ml/ square meter with 10% gelatin. This would not be impossible.

PE

 

[sanking]

Ron can answer this of course, but 10 g./ sq. meter would be using 100 ml of your 10% gel. sol. for every sq. meter you coat... what? 100 ml? 100 g. solution? I think.

It sounds like you might be using considerably more than this...

How many mls do you use to coat 1 square meter of.... tissue?

Ray

From 800 to 2000 ml of pigmented gelatin solution per sq meter, depending on kind of relief desired.

Sandy

 

[Photo Engineer]

Sandy, at 10% gelatin, that works out to 200 g (100 g/liter in 10%) per square meter of gelatin and not the figure that I thought was the case. That coating is very heavy. If you are coating at 1 mm gap witdth, then you can calculate the actual value by calculating 1 meter x 1 meter x 1 mm to get the theoretical volume of your coating. If there is little waste scraping the top, then if you use more than 100 ml, the gap is not 1 mm.

PE

 

[sanking]

Sandy, at 10% gelatin, that works out to 200 g (100 g/liter in 10%) per square meter of gelatin and not the figure that I thought was the case. That coating is very heavy. If you are coating at 1 mm gap witdth, then you can calculate the actual value by calculating 1 meter x 1 meter x 1 mm to get the theoretical volume of your coating. If there is little waste scraping the top, then if you use more than 100 ml, the gap is not 1 mm.

PE

Ron,

I vary the height coating since this is the mechanism I use to determine relief effect.

You probably don't know how I coat carbo tissue. Here are the rudiment of the details. First, I level (absolutley) a large flat surface, on which I then place a piece of galvanized sheet metal, much larger than the surace I intend to coat. Next, I place a piece of tissue support on the sheet metal, then squeegee away excess water. Over th paper goes a frame of magnetic sign material, of the desired thickness of the carbon tissue. Then, I calculate the amout of pigmented gelatin needed to fill the frame and add about 10% more. I pour this amount into the center of the frame, spread it out, and then roll a heated tube ove the surface. The height of the magnetic sign material in essence detemines the height of the coating.

I have some illustrations of this in my book on carbon printing.

Sandy

 

[Ray Rogers]

Ron,
If I did the math correctly, one liter could be right.

I belive
1cc is 1000 cubic mm
so
1000mm x 1000mm x 1mm = one million cubic mm

and since 1cc is 1000 cubic mm
one million cubic mm / 1000 cubic mm = 1000 cc

One Liter

Sandy must be varrying the gap or relying on surface tension or something....

 

[Ryuji]

My question remains, because I can make better emulsions than what you have been posting around, by using public information only (and avoiding infringing patents). I can get anywhere between grade 0 and 4.5, and I can get speed much above ISO 25 for negative emulsions. I have no secret, and I've been sharing with others some of these information as well as actual images I made with those emulsions. Some of these emulsions are very simple and do not require anything that aren't available from regular photographic chemical suppliers. So how useful is your "proprietary" information?

Ryuji, as you know, I intend to eventually donate the formulas I come up with to the general public. I am trying to come up with easy to make formulas that do not use proprietary Kodak information, but which are simple enough for most people to make in their darkrooms. I am trying to compile a list of sources and resources to accompany the formulas so that a person can purchase a 'kit'.

I am trying to make as wide a range of paper grades as possible (1 - 4 hopefully), and one orthochromatic film formula with decent camera speed (ISO 25 or higher hopefully).

 

[David A. Goldfarb]

Given the immanent demise of Azo, some of us might be more interested in a simple slow chloride emulsion using hundred-year-old technology than something faster or more modern. It might be slower, less practical, and yet more beautiful.

 

[Photo Engineer]

David, that is one of my goals. I just hope I can achieve it.

Ryuji, I'm glad to hear your results are so good. I have stated my goals. I am not there yet, and may never get there to my satisfaction. But that is for others to judge by trying out the actual formulas or seeing my results in person.

I agree that both your formula and mine are simple and right out of the book. Yours appears to be a close analog of the emulsion disclosed in Kodak publication AJ-12 and posted on this form in the formulas section. It is also similar to the formula disclosed by Jim Browning which he used to make Matrix Film.

There is nothing new under the sun unless you get to 'art'. And that is my point.

When we got 10 engineers into a room to discuss emulsions, there were usually 20 opinions. The bottom line was that the best and simplest way was inevitably chosen. If mine is not good enough, I will happily abandon it. I have nothing to gain or lose.

PE

 

[Ryuji]

Given the immanent demise of Azo, some of us might be more interested in a simple slow chloride emulsion using hundred-year-old technology than something faster or more modern. It might be slower, less practical, and yet more beautiful.

Slow chloride emulsions are easy to make but not easy to get good tonality with very low fog and decent Dmax. With the simple methods, both shadow and highlight will come out too soft compared to the midtone contrast. This is good if you want old timey look, but if you want something comparable to Azo, you would have to use a more complicated setup to mix the emulsion than what Ron does.

If you are interested in old time chloride emulsions, look for numerous publications by Steigmann. As usual, the gelatin he used is old type quite different from today's gelatin, and also he used cadmium so you have to adapt the formula to work with modern gelatins, as well as non-cadmium dopants.

Patent literature from mid-1990s to present is rich of information regarding chloride emulsions. They are used in scanning laser exposed color papers to print digital images. But the design of crystals are applicable to b&w work. Just use different dyes or no dye at all.

Finally, chloride emulsions are far easier to get fogged by accidents other than light exposure. They require very careful selection of paper and sizing procedure to avoid fogging defects. I generally don't recommend chloride emulsions to beginners for this reason alone.

 

[Photo Engineer]

Sandy, my misunderstanding. I am sure that this is a very thick layer and hard to control properly. That is 100 g of gelatin / meter squared, and much thicker than what I coated, but not out of bounds for an extrusion or slide machine.

The instant products had very thick layers to get acid timing correct and to get diffusion correct. I'm sure that this could be done with high quality.

Ray, of course your calculations are correct. Thanks.

PE

 

[Photo Engineer]

Ryuji, I use Strathmore paper off the shelf and do not fog the chloride emulsion at all. I can coat it with a paint brush or by a method much like Sandy uses albeit at a lower weight per unit area.

I have picture comparisons with Multigrade IV paper, as I said, and the contrast and tone compare favorably. It is not Azo paper, but it has a good black tone, an old time look and the right contrast.

PE

 

[Ryuji]

I don't know which of my formulae you are talking about, but none of my current emulsions is anything similar to AJ-12, which is a very lousy formula anyway. All but the simplest example I give away to people, I use dopants that are not used in any formula you mentioned, and also all but the simplest of my emulsions are core-shell structure with multiple growth steps (using triple jet) of different halide compositions. Plus, I use S+Au+R sensitization for negative emulsions. Now I've had success with t-grain so I'm moving to t-grain emulsions.

Another interesting emulsion I make is <111> bounded AgCl emulsion using habit modifier. This type of emulsion is not used in commercial products because they are very difficult to sensitize with dyes, but they actually work beautifully for b&w paper applications.

I agree that both your formula and mine are simple and right out of the book. Yours appears to be a close analog of the emulsion disclosed in Kodak publication AJ-12 and posted on this form in the formulas section. It is also similar to the formula disclosed by Jim Browning which he used to make Matrix Film.

 

[Ryuji]

Strathmore makes several different kinds of papers, some of which I used in the past. They may not fog your primitive (non-digested) AgCl emulsions but they fog S-digested AgCl and AgClBr emulsions very badly. This is true of most, if not all, papers I tried anyway.

Ryuji, I use Strathmore paper off the shelf and do not fog the chloride emulsion at all. I can coat it with a paint brush or by a method much like Sandy uses albeit at a lower weight per unit area.

I have picture comparisons with Multigrade IV paper, as I said, and the contrast and tone compare favorably. It is not Azo paper, but it has a good black tone, an old time look and the right contrast.

PE

 

[Photo Engineer]

Ryuji, I've tried 3 different types of Strathmore including Watercolor, Smooth, and Vellum. I've coated AgCl, AgClI, AgBr, and AgBrI on them as well as AgClBr. I have had no fog. I have also coated an optimally sensitized (sulfur) AgBr (along with all of the iterations to get there) on these papers. None of them had fog. I've also coated the AgCl and AgBr along with AgClI and AgBrI with spectral senstizer, and the only fog problem I had was with "J" aggregation.

I've even coated on digital paper with the micro ceramic surface. It was foggy but surprisingly good all things considered.

I have used Cranes and Lanaquarelle with no fog.

I have used weights from about 75 # up to 300 # paper with varying texture to examine effects suitable for the 'old time' look.

PE

 

[Photo Engineer]

Ryuji, your emulsions sound too complex for the hobbyist.

They are probably superb, but the average user will not want to do things at that level of complexity.

PE

 

[Ryuji]

I'm not surprised. You are not coating optimally S-sensitized AgCl or AgClBr on bare paper. THis is the combination that causes fog. Optimally S-sensitized AgBr emulsion may have slightly elevated fog or slightly modified toe curve but they are not prone to fog as badly as AgCl emulsions.

I'm not surprised with your fog problems with dyes either. You are not using effective stabilizers like PMT and TAI. If you use dyes, these are a lot more critical. (Au sensitization is also tricky and very prone to fog if not done right.) But if you want speed, these problems are unavoidable. You could set lower expectation and avoid all these problems, as well.

Ryuji, I've tried 3 different types of Strathmore including Watercolor, Smooth, and Vellum. I've coated AgCl, AgClI, AgBr, and AgBrI on them as well as AgClBr. I have had no fog. I have also coated an optimally sensitized (sulfur) AgBr (along with all of the iterations to get there) on these papers. None of them had fog. I've also coated the AgCl and AgBr along with AgClI and AgBrI with spectral senstizer, and the only fog problem I had was with "J" aggregation.

I've even coated on digital paper with the micro ceramic surface. It was foggy but surprisingly good all things considered.

I have used Cranes and Lanaquarelle with no fog.

I have used weights from about 75 # up to 300 # paper with varying texture to examine effects suitable for the 'old time' look.

PE

 

[Ryuji]

The only way that makes sense to me is to make a good emulsion first and simplify from there. There is no point to muck around with ancient formulae endlessly. Some of the t-grain emulsions are actually easier to make, if you compare among emulsions of a same speed.

Ryuji, your emulsions sound too complex for the hobbyist.

They are probably superb, but the average user will not want to do things at that level of complexity.

PE

 

[Photo Engineer]

Ryuji, please note that I get fog in one case only.

AgBrI with a dye that tends to form a "J" aggregate. This aggregate forms before coataing and the fog came from my safelight. You apparently don't know that a "J" aggregate, named after Dr. Jelly at Kodak, shifts the spectral sensitivity to longer wavelengths. Since I was expecting a green senstization, and the shift went into the red, my red safelight fogged the emulsion, not the paper.

The same dye works fine on other emulsions.

PE

 

[Ryuji]

Ron, you are the master of forgetting things. You asked me about dyes and J aggregate on photo.net a few months back when you were playing with erythrosin and I responded with details. Now are you telling me that I don't know J aggregate? Funny.

Your story is phony. If you are using one of the ortho dyes with J-aggregate which gets fogged by red safelight, I think your red safelight has serious problems that make it useless in practice. If the dye renders the emulsion red sensitive by merely using a concentration for J-aggregate formation, that dye shouldn't be called ortho dye to begin with. Either way, your story sounds like a poorly written fiction.

Ryuji, please note that I get fog in one case only.

AgBrI with a dye that tends to form a "J" aggregate. This aggregate forms before coataing and the fog came from my safelight. You apparently don't know that a "J" aggregate, named after Dr. Jelly at Kodak, shifts the spectral sensitivity to longer wavelengths. Since I was expecting a green senstization, and the shift went into the red, my red safelight fogged the emulsion, not the paper.

The same dye works fine on other emulsions.

PE

 

[Keith Tapscott.]

...emulsions I mean?

I am doing it a lot - have done it for many many years, but as the galleries in here doesn't tell much, I was qurious to know, whether I am alone in my bliss, or if there were others "doing it"....

(LE beats almost all papers! prove me wrong...)

It`s good to see that there are photographers who use liquid emulsions.
I`ve never tried this myself, but I have been looking at the images in Lee Frost`s Simple Art of Black & White Photography book, chapter nine shows some prints made by Lee using SE1 emulsion coated on to Fabriano Paper.
Papers mentioned are Fabriano Artistico, Fabriano 5, Arches Aquarelle, Arches Platin and Cranes Parchment. The book makes me want to try this soon, so it`s nice to read of practioners experiences with this imaging medium.