Red Sensitive Dye ?

[wildbillbugman]

Keep that Sands dye alive guys.

Here is the big secret! It is the red sensitizer for KODACHROME! It is one of the few dyes that can survive development and still be active. So, someday, if there is a researcher who wants to recreate Kodachrome, this is the dye to use.

PE

H

Yeh, what was it,27 layers? I am glad that I have ZERO interest in color film, homemade or commercial. Gimme color separation any day. I have been that way ever since I first read about how Technicolor worked. STILL the best process ever.

 

[Photo Engineer]

Not that many, and it sure was sharp!

PE

 

[falotico]

People will be harvesting the Kodak patents for a thousand years. I have always thought the Kodachrome structure was a robust design, saving a lot of work which would be required for built-in couplers and the manufacture of chemicals which would be stable in the field. Its principal innovation was to solve the registration problem which was an issue with Technicolor DT. Kodachrome will still be with us in one way or another. Now that PE has revealed the red light sensitizing dye, Kodachrome is yet another step closer to becoming an amateur-built process.

I share the admiration for what was traditionally called the Technicolor 3-strip process. The camera was essentially a "one-shot" design and the separation negs which it produced tended to have higher contrast high-light to low-light than the separations produced in chromogenic films. Technicolor DT prints therefore often had a fully saturated portion of the frame. This can be very satisfying to color lovers as well as producing a very deep gamma black--darker than most chromogenic blacks. Also the process allowed considerable latitude to produce the final "look" of the film. Technicians could work in daylight balancing contrast and gamma. More importantly they could use a wide variety of dyes and dye mixtures to produce the hues, all of which could be found on the commercial market. Chromogenic films could only use dyes which were produced by coupling-development. This limited the dyes available so that hues and saturation could suffer. But Technicolor could mix up a separate soup of dyes for each new film it produced. In addition, two or more dyes could form the complementary colors. The process made the human face look beautiful and allowed for very pure tones in the low-lights. This made for rich sunsets and clear views of dark interiors. I doubt if "The Godfather" would have looked as good if it had not been printed in Technicolor DT.

Finally there is the stability of the dyes--for years the best in the industry. About six months ago I saw a Technicolor DT print of a short of the World's Fair in Flushing Meadows which was printed up in 1964. The film looked like it had been produced yesterday. DT prints are some of the most satisfying images in analogue photography.

 

[wildbillbugman]

I have 3 of those one-shot cameras. In various stages of restoration. Man! if anyone thinks that view cameras are "complicated", get a one-shot 5x7. Alignment of focal planes is a bitch. But God made black and white film. The existence of color film was one of mankind's mistakes. Lie bird feeders. Eeck.

 

[falotico]

Good lord, I have a whole gallery of color photographs of bird feeders! Now I realize that I have made a ghastly mistake! They should have been photographed in black and white.

 

[wildbillbugman]

That's OK falotico. Many people have regrets about their lives. Wasting ones life on color film is a hard fact to accept. Kind of like realizing that you rejected your Soul Mate because you were too shy.

 

[wildbillbugman]

Bill;

In practice, you must determine the best level of dye by trial and error. I always do a concentration series.

And, the amount varies from emulsion to emulsion and of course if you want J aggregation it takes 2x the amount, however if aggregation is going to take place it will and may only cover 1/2 of the emulsion. Therefore it is best in this case to optimize for the aggregate to form rather than some sort of mix.

PE

PE,
Since SD3057 without J aggregation is a green sensitive dye, Would it not be possible to create an RGB sensitive emulsion by aggregation of only some of the Ag halide-dye?.
I have never attempted to produce panchromatic emulsion with only one dye. But care with both concentration and mixing of the dye might make this possible.
Or, is my neighbor smoking something that is drifting over here? THAT is a real possibility. It ain't my fault. This is San Bernardino. Drugs are all over and used by people you would never suspect.
Even Retired Kodak engineers,PE.:munch:

 

[Photo Engineer]

Bill, it is indeed possible to make a pan sensitive emulsion with this dye, but you must remember that it re-equillibrates in the melted emulsion and in the coating as it keeps (although this is very slow). So, what you get is a changing emulsion.

Remember that J aggregation depends on Iodide content and thus it is possible to get red and green by using an Ag/Br/I and Ag/Br mix provided that you can get them up to comparable speeds and curve shapes kinda match.

PE

 

[wildbillbugman]

Thanks PE,
This shall be my next emulsion. Hopefully not the next and the next and the next.--------------------------------------------------------------------
Bill

 

[wildbillbugman]

PE,
Some years back, you indicated that for a panchro emulsion, it is best to mix a each dye into a separate section of emulsion, then mix the 3 portions. Then, just a few months ago, you said that a blue sensitive portion, with no dye was not required. I have found the latter to be true I think that my next emulsion will contain only SDA3057. Half will contain only Br,or Br plus a small amount of I. The other half will contain Br plus a greater dose I.
Comments?
It has occurred to me that, because my work involves in camera color separation, I do not need a panchro emulsion. I could just use 3 differently sensitized emulsions.

 

[wildbillbugman]

Or just two differently sensitized emulsion.
Denise is having success with a one dye, panchro system.

 

[Photo Engineer]

Bill;

A two dye panchro system will work due to the blue speed inherent in all AgX emulsions. In fact, with the right dye, a single dye panchro system is possible, but I have not found any good dyes on the open market for this type of work.

As for having achieved a given sensitivity, it is always useful to have separation exposures or wedge spectrograms to prove any given sensitivity. I learned that the hard way many many years ago.

PE

 

[kb3lms]

Stock Solution

Now that I am finally getting to a point that I will be able to try out my small stock of Eastman 2718 (aka Stains-All) dye, what is a good stock solution? My plan is to make up a 25ml dropper bottle to use for my experiments. I was thinking about a 1% stock solution in ethanol. Here is my reasoning:

My emulsions almost always use 6g of AgNO3. At a molar mass of 169.87 for AgNO3, that gives 4% of a mole of silver. So if I was to use the dye at, say, 100mg / mole Ag, 6g AgNO3 would require 4mg of dye. (100mg/mole is a starting point. IDK what will actually work but 100mg make the numbers work out easier.)

A 1% solution of dye should contain 10mg dye per ml, so I could use 0.4ml stock solution or about 8 drops.

Sound OK?

-- Jason

 

[Photo Engineer]

I would use a more dilute solution so that you can measure it out more accurately. After all, 4 ml is easier to measure that 0.4 ml.

It is the word "about" that bothers me.

PE

 

[kb3lms]

OK, that is a thought. I suppose the extra ethanol wouldn't hurt since I always add some at coating time anyway.

I should have added that this batch of dropper bottles I have has ml marking on the droppers and also since it is roughly 20 drops to the ml that is why I said about 8 drops.

I also have 1ml syringes.

Anyway, then it seems like I am thinking along the right lines? At the cost of this stuff I'd rather not mess it up! (Actually, what I have was pretty cheap, but to replace it won't be.)

Thank you for the info!

 

[Photo Engineer]

You are doing OK.

PE

 

[wildbillbugman]

Hi Jason,
I am super-interested in your results regarding KODAK Stains-All. But is it something that can still be purchased? Do you have a structure for it?
Bill

 

[Hexavalent]

Stains-all is a fairly common histological dye with an impressive chemical name: 1-Ethyl-2-[3-(1-ethylnaphtho[1,2-d]thiazolin-2-ylidene)-2-methylpropenyl]naphtho[1,2-d]thiazolium bromide, 3,3′-Diethyl-9-methyl-4,5,4′,5′-dibenzothiacarbocyanine .

Whew! Stains-all is easier to pronounce. Note that it's a carbocyanine.

Sigma-Aldrich: http://www.sigmaaldrich.com/catalog/product/sial/e9379?lang=en&region=US

 

[kb3lms]

Bill,

It'll be a little bit before I have results. First, I have to get the freakin mice out of my workshop and reorganize. It got cold all of a sudden and of course they all wanted to come inside!

Stains-all is readily available from a number of suppliers. There's Sigman and Fisher, of course, but Lab Depot, Chemsavers, and other such places list it as well. It sells in the range of $100/gram. Search under "Stains-All", not the impressive chemical name. The CAS Number is 7423-31-6.

I've started wondering if my doctor (as in MD) could order these histological dyes from their suppliers? He does some of his own lab work with microscopes, etc, for fun, I guess; he has a whole little lab setup in the back of his office building. Most of the dyes we are interested in have some use in that field as well.

-- Jason

 

[wildbillbugman]

Thanks Jason,
I may try to get some of this dye. I am currently doing more experiments with the Sands sda3057. Using it as a single, panchro dye. Should have some results by Saturday. If I get it to work, I will run with it, despite its high price. Bill

 

[wildbillbugman]

I hope that you are getting rid of the mice in a humane ,non-lethal way.

 

[rwhb12]

So, PE, what is the optimum dye colour for Panchromatic emulsions please, if you were aiming for a single dye solution? I guess every emulsion had a different blue?

Russ

 

[kb3lms]

I think I will have to put out a want-ad for a cat.

 

[wildbillbugman]

Jason,
I was not going to put this out until I had more data, But as long as you have asked PE the question , I will say this. An Ag/Br emulsion (with no I) containing SDA3057, is red. Addition of NH4I causes the emulsion to immediately turn to a lavender-blue. Of course, I determined this by pulling small samples and looking at them under white light. The containers of emulsion are always in the dark, or under IR light.

 

[wildbillbugman]

Question for PE,
PE, I now have 2 sets of glass panels waiting for evaluation. Set 1 is a 50/50 blend of 2 emulsions containing SDA3057 . Emulsion 1 contains no Iodine and is red.Emulsion 2 is emulsion 1 plus Iodine and is lavender in color.
Panel set 2 is Pure emulsion 2 ( contain I) (lavender) coated first. Then a second coat of pure emulsion 1 (no I) (red in color).
Any predictions?