Electro Analog Colour (EAC) instant photography (Kirlian photography)

[hsandler]

Experimenting with an old fad from the 60s and 70s recently, known as Kirlian photography. High voltage is applied to a conductive flat object resting on a sheet of film over a grounded metal plate. High voltage corona discharge creates blue and uv light which exposes the film. I tried this with a sheet of Instax wide tonight and it works well!

Electro Analog Colour (EAC) instant photography by Howard Sandler, on Flickr

 

[koraks]

Cool!

 

[loccdor]

It is very interesting. I wonder what techniques could be used to get colors other than just blue. It seems like there's a lot of room for additional experimentation. And can the resolution be increased by using a different film?

It does kind of remind me of the special effects that 80s movies had.

 

[koraks]

I wonder what techniques could be used to get colors other than just blue.

You could get a red-yellow-white gradient by flipping the sheet of film.

By nature of the process, the image formation will be the strongest on the side of the film where the discharges occur. Given the layer order on color film, this somewhat limits the colors you can get. It would be impossible, for instance, do do a pure green-white gradient. Whatever you do, it'll always involve a heavy emphasis on either the red/cyan-dye layer, or the blue/yellow-dye layer. In this case the latter.

 

[hsandler]

You could get a red-yellow-white gradient by flipping the sheet of film.

By nature of the process, the image formation will be the strongest on the side of the film where the discharges occur. Given the layer order on color film, this somewhat limits the colors you can get. It would be impossible, for instance, do do a pure green-white gradient. Whatever you do, it'll always involve a heavy emphasis on either the red/cyan-dye layer, or the blue/yellow-dye layer. In this case the latter.

Now I’m intrigued and have to try that!

 

[titrisol]

Depending on the element, and the pressure you can get other colors
I helped a friend build one for 35mm film in my college years and it worked fine for fingers, leaves, etc.

Living things create colorful electric fields, myguess is that field distributes unevenly, and (especially fingers) pressure also plays a role

 

[hsandler]

Now I’m intrigued and have to try that!

Update: It doesn’t seem to cause any exposure with the print image side of the instax sheet towards the metal object, at least not with the voltage I’m using. Perhaps one of the layers in there starts out opaque to uv light, or it may have to do with conductivity of the layers. I could hear the sound of corona discharge when I did the exposure.

 

[Richard Man]

One of my high school friends at Stuyvesant in the late 70s was into that and entered science fairs with it. If you know Stuyvesant, you know that there were (are?) tons of science and math people there. Good fun. For a while, people were also using it to do "Aura" photography.

 

[Harry Callahan]

It is very interesting. I wonder what techniques could be used to get colors other than just blue. It seems like there's a lot of room for additional experimentation...

What about putting a color filter between the key and the film? As the bright flashes are rather white, other colors should be contained.

 

[koraks]

What about putting a color filter between the key and the film? As the bright flashes are rather white, other colors should be contained.

Who knows, but I think the idea is that most of the 'exposure' is caused by the direct injection of electrons into the silver halide crystals by the spark itself. I.e. it's not really the light that does it. Then again, one doesn't exclude the other, so it may be worth a try.

 

[hsandler]

I don’t see any light at the voltage I can achieve, unless there is an arc. I think most of the light is UV.

 

[koraks]

Nah, if you don't see any light, this supports what I said - that the actual 'exposure' is electrical, not optical. If the spark isn't energetic enough to produce visible light, it won't make UV either.

 

[hsandler]

Nah, if you don't see any light, this supports what I said - that the actual 'exposure' is electrical, not optical. If the spark isn't energetic enough to produce visible light, it won't make UV either.

It's possible, but I'm going by this paper which suggests most corona in air is in the near UV region. https://www.mdpi.com/2226-4310/9/9/524

 

[calebarchie]

I have an entire book on this subject Photographing the Nonmaterial World by Johnson, K.L. (1979) pretty interesting. A fellow artist Sean utilises this process for his works.

high voltage spark imaging — oneorangedot

high voltage spark imaging of materials - moving towards an understanding of what it is like to be electric - exploring the internal landscape of matter through the movement of electrons....

www.oneorangedot.com

 

[Harry Callahan]

Who knows, but I think the idea is that most of the 'exposure' is caused by the direct injection of electrons into the silver halide crystals by the spark itself. I.e. it's not really the light that does it. Then again, one doesn't exclude the other, so it may be worth a try.

I see.
I was reminded of the visible flashes you can produce with high voltage like with a Tesla coil.

But as its injection of electrons we probably need different electrons... ( )

Is it known where the blue-sensitive layer on a color film is? I mean if the electrons activate the silver crystals, they shouldn`t differentiate between different kinds of silver crystals. If the blue sensitive layer was the first or the last layer this could explain why blue is the dominant color (while there is a tad of green at the bottom of the picture).

EDIT:

And as there also is white on the picture, it should mean that electrons are passing through all color layers but seem to spread across the blue layer for the most.

 

[BrianShaw]

I took a class taught by Dr. Thelma Mass. Very weird stuff, and very interesting. Never did any Kirlian photography yet find it fascinating. It seems that trying to explain uysing physics, engineering, and logic is somewhat missing the point.

UCLA lab researched parapsychology in the '70s - Daily Bruin

The phone calls would come in, and the voice on the other side would ask, "Do you believe in ghosts?" This wasn't a prank.

dailybruin.com

 

[Harry Callahan]

But maybe it also is about electrical conductivity of the different layers. Depending on what chemicals are in each layer, each layer may have a different conductivity - the blue layer then being most conductive.

Maybe you could get other colors by "pre-soaking" the film, as a wet emulsion would increase conductivity of every color layer. But then voltage probably had to be reduced to not "over-expose" the picture.
And precautions to be taken not to suffer an electric shock.

 

[koraks]

Is it known where the blue-sensitive layer on a color film is?

Yes, it's the top layer in film (on RA4 paper it's the bottom layer).

And as there also is white on the picture, it should mean that electrons are passing through all color layers but seem to spread across the blue layer for the most.

There you go!

But maybe it also is about electrical conductivity of the different layers.

The question is not so much conductivity, but which silver halide crystals present the biggest cross section, making them the most likely to capture electrons, and of course also the sensitivity of the silver halide crystals will matter (higher sensitivity = less electrons needed to produce the same energy). In any case, the electrons will still have to penetrate all the layers that you want to create image density in.

Pre-soaking isn't going to do all that much; it may do something in terms of the charge needed to get the same exposure since the swollen gelatin will enlarge the space between the silver halide crystals - at least in the vertical orientation of the emulsion layer stack.

And precautions to be taken not to suffer an electric shock.

You don't need a lot of charge to get an image with this technique. It can be kept way below the level where there would be any danger.

 

[Harry Callahan]

As the blue layer is on top of the film, this means its easier for the electrons to spread on the emulsion surface than to go through the entire film.
Is the film held flat by a metal holder, being similar to the adapters you could get for glass plate holders to also put sheet film in?
Also, ain`t there color filter layers between each color sensitive layer - or am i mistaking this for Kodachrome process?
If there also are filter layers in between, these should act as an insulator, as they wouldn`t contain silver crystals to conduct electricity into the layer below.
If the film was wet, these "insulation-layers" should become more conductive, passing and spreading electrons easier into the color sensitive layers below.

Yes, if the gelatin is swollen the distance between sliver crystal will increase, but conductivity also will increase. If you wetten a non-conductive material like a rope for example, conductivity usually increases more than by factor two or three.
The question is what ratio is between greater distance of crystals to increased conductivity.
I assume conductivity will outweigh increased distance of crystals.
Therefore i also believe that voltage or timespan should be reduced to avoid "over-exposure".

Good to hear that there is no danger with wet film.

 

[koraks]

Also, ain`t there color filter layers between each color sensitive layer - or am i mistaking this for Kodachrome process?

Yes, there are. But the filtering layers are very thin. I don't think they do all that much w.r.t. insulation. If they did, there would be no discharge, after all! Keep in mind that there needs to be at least momentary conductivity for the discharge to occur in the first place. This means that if an exposure is present, this implies that very briefly, the entire emulsion stack plus the film base have been sufficiently conductive to allow a channel to be made.

I assume conductivity will outweigh increased distance of crystals.

I don't see how it's going to make much of a difference either way. It just means you may get away with a slightly lower voltage than on a dry emulsion. There will likely be visual difference, but more in terms of how the discharge spreads laterally (I expect it'll 'fork out' less spectacularly, creating a more focused image). And it won't change anything about the blue-sensitive emulsion being on top. It's worth a try, but my expectation is that a wet piece of film will actually give a less interesting image overall. It's easy enough to try with a piece of B&W RC paper to get a feeling for the differences between wet and dry.

 

[Harry Callahan]

What voltage is used to create these pictures?
I mean the higher voltage is, the more non-conductive material can be "sparked" through. The white "flashes" of course show that the electrons moved through the entire film, but they only made it because voltage was high enough to "spark" through a rather non-conductive material.
My take on the filter-layer rather is about blue being the dominant color. This means the electrons move quite a bit over the blue layer, but don`t make it to the layer below (unless they "spark" through all layers).
Therefore it looks like there was an insulator between the blue and the next layer, keeping the electrons from moving deeper (unless "spark").
As the filter layers don`t contain silver crystals, they should be less conductive than a color-layer - and by wettening this should be reduced.
The filter layers are thin, but blue is the dominant color, indicating insulation to the other layers.

If voltage and timespan is kept the same, a wet film should show more "exposure", more white "flashes". These "flashes" should be even longer, as now conductivity is increased making it easier for the electrons to travel through and along the film.
That's why i would reduce voltage or timespan to avoid "over-exposure" with a wet film.
But there also are several blue areas without a white "flash" in them or near them. These areas i expect to also show other colors but blue.
In these blue, but "unflashed", areas the electrons activated the blue layer without sparking through the entire film, but they only activated the blue layer as if there was an insulator to the layer below. With water conductivity to the layer below should be higher and by that additional colors should occur.
But also more white "flashes" as now its easier to spark through the entire film, that`s why i`d reduce voltage or timespan. Some testing was required to find the proper "exposure".
.....

In the end a wet film at least should proof whether its about UV-light or electrons traveling through the film. If it was UV-light exposing the film, a wet film shouldn`t show big a difference - if it is about electrons traveling a wet film should show big differences.

 

[koraks]

My take on the filter-layer rather is about blue being the dominant color. This means the electrons move quite a bit over the blue layer, but don`t make it to the layer below (unless they "spark" through all layers).

That mechanism doesn't have to rely on any filtering. Just fanning out and eddy currents on the surface layer will do the trick.
So no, I don't think your reasoning is necessarily correct; I see no evidence in this experiment of significantly higher impedance of the filter layer compared to other emulsion layers. From a viewpoint of the chemistry of the layers involved, I also don't think it's likely.

That's why i would reduce voltage or timespan to avoid "over-exposure" with a wet film.

I understand. But in principle, it wouldn't make a difference whether you 'expose' with a lower-voltage (and/or charge) spark on wet film compared to a higher-voltage spark on a dry film.
Of course, it does probably make a difference, but mostly in the pathways that the discharge will choose. So the pattern will likely change. How it will change is virtually impossible to predict unless you build a pretty accurate and fine-grained electrical model of the whole setup. The example image shown earlier doesn't contain sufficient information to do this.

With water conductivity to the layer below should be higher and by that additional colors should occur.

All electrons that go through (some of which are captured by silver halide crystals) the other-colored bottom layers will also go through the top layer. So the flash will still be white in the areas with high intensity. The way to change this is to apply a smaller electrode (i.e. the object that's being 'photographed') on the bottom side of the film instead, in which case eddy currents and fanning out will favor formation of image density at the bottom of the film stack - i.e. cyan dye, or a red image. See my initial response.

In the end a wet film at least should proof whether its about UV-light or electrons traveling through the film. If it was UV-light exposing the film, a wet film shouldn`t show big a difference - if it is about electrons traveling a wet film should show big differences.

That bit I do agree with.

 

[Harry Callahan]

Unfortunately i don`t know about the chemicals in the filter layers, but i know that electricity always does take the path of lowest resistance.
Also i know that silver is very conductive, even a bit more conductive than copper - and the filter layer below the blue-sensitive layer does not contain silver afaik.
So the filter layer may be very thin but should be less conductive than a layer containing silver - and most of the colors in the picture is blue.

Basically the electrons show us that they don`t want to enter any deeper layers unless voltage is high enough to go through the entire film. Then there is a white "flash" and a blue surrounding, indicating that the blue layer is easier to access for the electrons than other layers.

I don`t expect the "flash" to change in color. There still should be white "flashes", due to increased conductivity i expect more and longer "flashes" - but a rainbow-like color pattern around the flashes and more colors where this picture only shows blue.
There are several areas where the blue layer has been activated without a white "flash" nearby (left edge, upper edge of the picture). Especially in this areas i expect more colors to occur but blue only.

 

[koraks]

Also i know that silver is very conductive, even a bit more conductive than copper - and the filter layer below the blue-sensitive layer does not contain silver afaik.

The silver is not present in a contiguous layer. It's dispersed in a gelatin matrix. Electrons will still have to 'jump' the high-resistance spaces between the silver halide grains. Moreover, what you still seem to not realize is that the current goes all the way through the film (including the substrate). The electrons, by and large, don't walk out of one electrode and then somewhere halfway the emulsion stack give it up and sit down. The current goes through the entire film stack. Only some of the electrons will be captured by silver halide particles and create 'exposure'.

And some blue filter layers actually are based on metallic, colloidal silver (Carey Lea silver). It depends on the film used. Either way, the filter layer is a very thin layer and the fact that image density is present means that the voltage is plenty high enough to jump that layer as well as all the other layers of the film stack, including the base, which is more than an order of magnitude thicker than the emulsion and a very good insulator.
Keep in mind also that there's a relatively thick topcoat on the film surface which the current also has gone through.
The blue filter layer really doesn't do much or anything in terms of 'filtering' electrons of this current.

The whole argument you're setting up confuses how electrical currents work with how photos hit a film emulsion. The total flux of electrons and their total energy load is so massively much bigger in the case of a corona discharge exposure as shown here compared to a regular light exposure.

indicating that the blue layer is easier to access for the electrons than other layers.

Yeah. It's the layer closest to the electrode. Again, flip over the film and the fanning out turns red.

There are several areas where the blue layer has been activated without a white "flash" nearby

Assuming they are actually image-density (and not e.g. a scanning artefact: they're likely eddy surface currents as I said above in #22. It is possible that when flipping the film over, these eddy currents won't show up anymore since they would happen on the substrate instead of closer to an image-forming layer.

Anyway, there's lots of experimentation and model building to be done if we would want to figure out the mechanisms involved.

 

[Harry Callahan]

The silver is not present in a contiguous layer. It's dispersed in a gelatin matrix. Electrons will still have to 'jump' the high-resistance spaces between the silver halide grains. Moreover, what you still seem to not realize is that the current goes all the way through the film (including the substrate). The electrons, by and large, don't walk out of one electrode and then somewhere halfway the emulsion stack give it up and sit down. The current goes through the entire film stack. Only some of the electrons will be captured by silver halide particles and create 'exposure'.

I am aware that between the each silver crystal in one color layer still is gelatin and the electrons have to "jump over". But because of the filter layer not containing silver, "jump over" to the next silver layer below will be harder than to expand in the blue layer.
I am aware that the electrons have to make it through every layer, including the acetate base, to create a white "flash". Also i am aware that resistance of the acetate is even higher than of the gelatin layers (and there also is the AHL ).

But when there is a white "flash", the surrounding of the flash is blue (for the most). This means around the white exposure, electrons don`t "jump over" in any layer but blue. If the gelatin was wet, "jump over" in a single color layer - lets say the green layer - should be easier and therefore other colors should occur but blue only.
Around the white exposure other colors but blue should occur.

And some blue filter layers actually are based on metallic, colloidal silver (Carey Lea silver). It depends on the film used. Either way, the filter layer is a very thin layer and the fact that image density is present means that the voltage is plenty high enough to jump that layer as well as all the other layers of the film stack, including the base, which is more than an order of magnitude thicker than the emulsion and a very good insulator.

Which is why i`d reduce voltage if the film is wet.

Keep in mind also that there's a relatively thick topcoat on the film surface which the current also has gone through.
The blue filter layer really doesn't do much or anything in terms of 'filtering' electrons of this current.

I say that the electrons seem to spread best in the blue layer. The dominant color is blue, even around a white exposure. For whatever reason electrons refuse to enter a different layer and give us a green, yellow or purple corona around a white exposure.

The whole argument you're setting up confuses how electrical currents work with how photos hit a film emulsion. The total flux of electrons and their total energy load is so massively much bigger in the case of a corona discharge exposure as shown here compared to a regular light exposure.

And because of that a white "flash" is clear. This part of the film is over-exposed.

Yeah. It's the layer closest to the electrode. Again, flip over the film and the fanning out turns red.

I want the fanning also to enter one or two color layers below the blue layer.

Assuming they are actually image-density (and not e.g. a scanning artefact: they're likely eddy surface currents as I said above in #22. It is possible that when flipping the film over, these eddy currents won't show up anymore since they would happen on the substrate instead of closer to an image-forming layer.

That's why i asked how the film is held flat during exposure i #19. If there is a metal holder, some of the electrons will move across the top of the film to the metal holder - and not "spark through" the entire film.

I also want these eddy surface currents to make it below the blue layer to give us more colors.
Which is why i want to increase conductivity between each layer.

Anyway, there's lots of experimentation and model building to be done if we would want to figure out the mechanisms involved.

A first step could be to just make the emulsion wet.
Or half of the film. One half wet, one half dry to see the difference.