Panchromatizing Spray or Liquid Emulsion for Autochrome

[Mustafa Umut Sarac]

I read many posts about Autochrome and developed my idea.

1- Buy a sheet of melinex.
2- Print a screen with original Autochrome dyes or Cheaper Starter equivalents with CMYK.
3- Tape printed side of melinex to the anti halo sprayed glass.
4 - Spray or coat the other side with emulsion.
5 - Take picture
6 - Develop
7- Remove the tapes and you have a autochrome.

I discussed this idea with Chris and he said that I needed to panchromatize the emulsion.

If I am not wrong , there were tube spray emulsions at the market.
How can I panchromatize sprayed emulsion before hardens ? Or can it be processed after hardening ?
If it is not possible , I would like to learn about panchromatizing liquid emulsions. What is the recipe ?

Thank you ,

Mustafa Umut Sarac

Istanbul

 

[Photo Engineer]

The problem is multifold.

1. You need to determine if the original emulsion is sensitive to other than blue.
2. If 1 = yes, then sensitize to the region(s) left out of #1. Hope that the new dye(s) do not remove existing dyes if any.
3. If 1 = no, then you need to get the proper pan dye to add and just add it with no worry.
4. Make sure you work in total darkness or IR.
5. Before you do anything, find a source for the dye.

Now, how to do 2 or 3. Dissolve the dye in an appropriate solvent for the dye. This will usually be at the rate of 100 mg - 1 gram / 100 grams of solution. This is then normally added at about 50 - 100 mg of dye / mole of Silver to the melted emulsion and held for 15 minutes with stirring before coating. All should be normal from this point on.

If the coating is already made, you will have to work entirely by trial and error to bathe the emulsion in dye solution to give the right sensitization. You should wash briefly after the soak in dye solution. This method is the least desired.

During this all, remember that the emulsion starts out with zero added sensitivity, increases speed in the desired region of the spectrum as dye level is increased, and then as you go up from there, both peak and blue sensitivity will decrease and development rate will decrease. Dyes are desensitizers and retarding agents at high levels.

PE

 

[Mustafa Umut Sarac]

Where can I buy pan dye from ? Is it only one or for every different spectrum ?
What are the spray or liquid emulsion brands which can be converted to panchromatic with one dye without worrying about the premixed dyes ?
Is it possible to panchromatize sprayed or coated dry emulsion ?

Thank you Ron ,

Umut

 

[Photo Engineer]

In Europe, IDK what companies sell dyes. You can make an emulsion panchromatic either by using one broad dye or two narrow dyes. The latter is more difficult.

PE

 

[Mustafa Umut Sarac]

Ron ,

Where do they sell these pan dyes at US ? I am still thinking to add to Liquid Light Emulsion and spray to back of the screen.

Umut

 

[Photo Engineer]

Try H. W. Sands Corp. in Florida. In Europe try Honeywell.

They might help.

PE

 

[Mustafa Umut Sarac]

Thanks Ron ,

I looked their website and there is sensitizers selection menu with wavelenght input function.
I sent every detail about my autochrome knowledge including sensitometry curves and asked Liquid Light to suggest me one of their emulsions and sensitizer selection.

I hope they help me. Otherwise , I will request curves and do whatever could be done on APUG .

Umut

 

[holmburgers]

from this book... http://books.google.com/books?id=fS...wAA#v=onepage&q=f.e. ives chlorophyll&f=false

In 1879 Mr. F.E. Ives suggested the use of chlorophyll of blue myrtle or periwinkle leaves for making collodio-bromide plates colour-sensitive. The chlorophyll is prepared by steeping the leaves, when cut into small pieces, in pure alcohol and heating for a few minutes. The solution of chlorophyll is in its best state when fresh, but will keep for some weeks in a cool place, if not exposed to light. To prepare the plates, flow with collodio-bromide emulsion, and when set cover for a few seconds with the chlorophyll solution, after which wash in distilled water until smooth. The plates must be used with the yellow screen, which Mr. Ives prapres by making a tank with plate-glass sides which is filled with a solution of potassium bichromate [modern equivalent; use a yellow filter]; the strength of the yellow solution may be increased or diminshed according to the subject to be copied. Excellent results have been obtained by this method.

Many kinds of colouring matter have been used for making plates colour-sensitive, amongs them eosine, erythrosine, cyanine, fuchsin, azaline, aurantia, rose Bengal, quinoline red, chlorohpyll, xanthophyll, gallocyanic (a blue dye), chrysanaline, corallin, aldehyde green. Most of these are derived from coal-tar distillation.

Chlorophyll; perhaps you could make this yourself Umut if you find the right plant.

Also, found here... http://books.google.com/books?id=O3...wAw#v=onepage&q=f.e. ives chlorophyll&f=false

F.E. Ives, colour-sensitive plates. A compound sensibilisator of fresh blue myrtle chlorophyll with a little eosin is found to be the most sensitive to yellow and green.

from Wikipedia - Vinca minor: Vinca minor, Lesser periwinkle and Dwarf periwinkle, is a plant native to central and southern Europe, from Portugal and France north to the Netherlands and the Baltic States, and east to the Caucasus, and also in southwestern Asia in Turkey.

 

[Photo Engineer]

Chlorophyll is usable but very weak and unpredictable.

PE

 

[holmburgers]

It'd be fun to experiment with though, and for the "budget-concious" it might be the absolute cheapest possible option.

 

[Photo Engineer]

I don't disagree, provided the expense of ruined emulsion and coating does not bother you. All experimentation with emulsions costs you the cost of Silver content and the paper and gelatin used along with everything else. It is sad to see someone lose a batch of emulsion because a chemical has gone bad or did not respond the same as the last experiment.

PE

 

[holmburgers]

That's certainly true. Riddle me this, would chlorophyll have any effect on standard b&w VC papers? I know it's hard to say w/o testing, but what do you think?

 

[Photo Engineer]

IDK. I've never tested it. And, if it fails, you have no way to tell if your chlorophyll was good and didn't work or bad from the start. Besides, for a reliable test you need a spectrosensitometer to test the coating just as I do. Or you need to give it pure red light exposures to test it.

In addition, chlorophyll is not a "true" red sensitizer. A true red sensitizer is cyan in color and not chlorophyll green. This is just an approximation.

PE

 

[Mustafa Umut Sarac]

Thank you Chris !

You got the big award.

Book says Chlorophyll could be coated to the dry emulsion plates for few seconds.

I think this open the gates because it is difficult to process liquid emulsion at full dark and if I can do it to sprayed dried emulsion , everything becomes easier.

Be sure , chlorophyll is one of the widest researched substance and you can find it from local university , biological medical distributor , lab or Sigma.

May be excessive amount of yellow comes from this formula at some autochromes.

May be Ron gives more detail.

 

[holmburgers]

But can other sensitizers be bought at remotely reasonable prices by a "civilian" individual?

The Lumiere's emulsion was supposedly not truly red sensitive, or so I've read. Due to Umut's interest in unique colors and representations, I think it could be a viable avenue.

But IDK either, I just enjoy giving a historical perspective, wherein old & forgotten methods might be resurrected.

 

[Mustafa Umut Sarac]

Ron ,

I think You are right , living organisms are not predictable.
What do you recomment to sensitize full spectrum ? To the dry plates .
Chris visit H. W. Sands Corp , go to catalog and search sensitizers - if this is correct - in red.
You can learn the nanometer from my french book scan post

 

[holmburgers]

I can't find sensitizers on their website for some reason. I recall that they are quite expensive, Ron would probably confirm that.

What do you mean from your book scan? As in, by analyzing the red/orange particle in the scan? As close as you can get to the upper 600's will be your best bet.

 

[Mustafa Umut Sarac]

 

[Photo Engineer]

Sensitizing dyes in general run about $100 USD / gram. But, since you only need a small quantity such as 10 - 100 mg / 109 g of Silver, this is quite a bit of dye to work with. For red sensitivity you need a dye that sensitizes in the region of 650 - 700 nm. If you go longer, then it is an IR dye.

There are several dyes that I have posted here that can be bought at Sands. The red dye is a "J" aggregate former though and is only a red sensitizer on a Bromo-Iodide emulsion. It forms 2 layers that turn a green sensitizer into a red sensitizer. It is, in fact, the dye used in Kodachrome.

PE

 

[Mustafa Umut Sarac]

Ron ,

You are seeing the graphic hereabove.
So please select the sensitizers which will work like above graphic minus liquid light graphic.
I dont know the sensivity of liquid light but you guess in your mind one.

Plus , at picture says that they did a spectrographic test to dyed starchs and
violet UV to 500
vertes 490 to 570
and orange 570 to 580 found.

Umut

 

[Photo Engineer]

The green curve here is mainly a blue and red dye or a "vague" magenta. Note that 3 colored materials are used but, in fact these dyes are far from anything used today.

PE