Experiments with RGB-colored screens... a la Dufaycolor & Autochrome

[holmburgers]

Right on Ron! I will check it out.

My long term worry is access to the necessary chemicals. Political, ecological; they're not in our corner I'm afraid.

 

[holmburgers]

Down & Dirty - But it Works

OK, these weird looking pictures are an attempt to align the screen with the film that was developed as a negative. I'm working on a method to keep them aligned so that I can actually scan them, but this is it for the time being.

The 1st picture is reality, and the 2nd picture has been flipped, revealing the positive image. It's not pretty, but the biggest proof is in that roll of blue painter's tape.

 

[holmburgers]

Ok, I have a theory as to why my gelatin-bound (and down? ) reversal processed negative ended as a complete and utter failure. I've noticed a strange phenomenon when an E6 transparency gets wet, it develops a strange green fog that doesn't disappear until it's dry again. And gelatin mixed with water would certainly exhibit this as well, migrating into the emulsion layer. If this fog was present at exposure, it would have resulted in severe underexposure, which would explain why my positive was as dense as osmium.

Glycerin however does not have this tendency to "wet" the emulsion; like oil & water, the two won't intermingle it seems. I also found a patent that discussed binding tri-pack layers with glycerin.

At any rate, I'm sick of the technical side of this and just want to start producing some good pictures by this method. Once I get down the binding procedure, that should become a reality... stay tuned.

 

[Photo Engineer]

All Kodak color products develop a slight color tinge on the surface due to the change in refractive index of the dyes in gelatin + solvent. This vanishes as it dries. The front (emulsion side) is yellow red and the back is cyan blue. The dmin areas are hazy or translucent.

PE

 

[holmburgers]

I'm thinking that the interior didn't have a chance (nor would it ever!) to dry, so this very well might be the problem. What is it about glycerin that doesn't exhibit this tendency? Is there something about it not mixing with gelatin?

I don't know how to word it exactly, but I recall Friedman mentioning something to this effect, in passing.

 

[Photo Engineer]

It is probably the index of refraction. If the indexes align, they retain their original transparency and color.

PE

 

[R Paul]

Hello guys
I don't want to hijack the thread, but I just wanted to show you the latest results with the lcd screen and tmx100 film. Sorry about the size,but this machine doesn't have anything on it to edit the photos . Alignment seems to be the big problem, compounded by the screen mounted in the plateholder, which makes it difficult to hold.
I was using xylene to bond the film and screen for viewing; it has the advantage of not getting the emulsion wet, and evaporates away. You would need something like kerosene or light mineral oil to hold the film for actual taking of the pictures, because it will stay around longer.

I see you've been laboring away at this too,Chris-- good work
and like any good photographer I manage to get my thumb in the picture
rob
P.S. I just realized that I could load the screen cassette with regular e-6 film ,take a picture of a piece of white cardboard on a sunny day or with flash, and make myself as many screens as I wanted. No CDU needed.

 

[holmburgers]

Rob, I'm so glad to see this!

I think it's fair to say that registration is the hardest thing about these screen-plates that are not integrated into the base of the emulsion. Have you managed to get the colors to pop into reality yet? In theory, there's only 1 possible position where all the color fringes/rainbows will disappear and the color reproduction will be at its best, and this tolerance is minute (less than the distance of 1 screen element).

Can you elaborate a bit on how the screen & film were situated, is that 120 film?

And for the record, I would never consider this hijacking. The biggest joy for me is encouraging other people to try it for themselves and indeed, I fantasize that my threads will become collaborative environments where people join in my methodology and share their results.

 

[R Paul]

Yeah it's 120 film. I thought I would do a proof of principle set before I ran out and bought a box of 4x5 You can get 5-6 pieces from a roll, so for 3-4 dollars I got up on the learning curve,with no guilt of blowing a whole sheet of film .
I basically just taped the film emulsion side out to the screen plate, hoping the back of the holder would hold it tight against the screen . I have been thinking of using kerosene or similar to couple film and plate, but then you get air bubbles that you won't know about untill it's too late. and it would probally mess up the foam backing as well
No, I haven't got them into alignment perfectly yet- managing the platholder plus my old eyes gives me troubles , it looks like a separate screen for each film is the way to go, but I think I've got a handle on that. All I have to do is shoot a white board on regular e6 through the screen --Instant screen! Then use a regular plateholder holding that screen and b/w film together and I'm good to go. At least I think so,or am I missing something?
rob

 

[holmburgers]

No, I think you're good to go. Do you have a plate holder with a spring loaded glass and foam back? That's absolutely the ideal method, and would probably fix all of my d@mn problems with binding the two sheets together!

Keep us updated rob

 

[R Paul]

No I don't have one of those-- but with a milling machine, a piece of phenolic board,and an old cassette for fixtures it won't be a problem. Thing is you have to make sure that the focal plane of the one you make matches an original cassette, or you'll go crazy trying to figure out why nothing is in focus-I usually measure from the front of the cassette down to the bottom plate where the film sits.

I made maybe four so far-including one with a mercury back for Lippmann photos
That one I only used once; and was very glad I was outside when I did!!
rob

 

[holmburgers]

Whoa! You did Lippmann with mercury?? This is too much for a boy at 2:20am. . .

I'm infinitely curious about this exploit; how many thermometers did it take?

 

[Photo Engineer]

I have about a pound of Hg here somewhere, free to a good home!

PE

 

[holmburgers]

What do you store it in?! May I ask why you have that?

Did I ever post that picture of a mercury holder? If not, here it is...

 

[Photo Engineer]

I have seen one of Lippmann's holders at GEH. They have drawings.

As for the Hg, it came from an old barometer and an old thermometer that I had years ago. Also, I was given some by a friend. We had some projects in mind.

PE

 

[michaelbsc]

I have about a pound of Hg here somewhere, free to a good home!

PE

Is it clean? Or does it need to be distilled?

 

[R Paul]

I only tried the thing once, shot two pictures and noticed the stuff leaking out everywhere. pictures were lousy-they were in contact too long with the mercury.
It took about 7-8cc to fill the frame-- really glad I did that in the boondocks
rob

 

[Photo Engineer]

It has oxide (scum) on the surface, but is chemically pure and does not need distillation.

PE

 

[holmburgers]

That must've been a huge barometer!

The fact that mercury is a powerful antifoggant has come up previously in this thread; I guess that quickness is the key?

Very fascinating indeed. . . , but wait, isn't this the screen-plate thread?

 

[Photo Engineer]

We digressed to Lippmann plates and other mercury oriented issues.

One pound of Mercury is about 30 - 40 ml. That aint much in a glass tube. And, you need a reservoir.

PE

 

[holmburgers]

We digressed to Lippmann plates and other mercury oriented issues.

Or did we progress?

 

[holmburgers]

Well, good news on the screen plate front. After first receiving a Linhof Pressure-Plate Film & Plate holder, I've now got two sheets of 0.55mm glass that beautifully sandwich two sheets of film together.

The whole setup is so effortless I'm kicking myself for not doing this earlier. That being said, I've yet to take any pictures, but it appears absolutely flush and there'll be no more messing around with ridiculous schemes that involve coatings or adhesives. Woohoo!

To commemorate this moment, here is a synopsis of pages 86 to 87 in J.S. Friedman's History of Color Photography, edited for dramatic effect:

To offset the possible effects of poor contact between the various members of the [sandwich], J.H. Smith coated the emulsions directly one on top of other, but with an insulating layer of collodion between them... Biehler accomplishes the same result by coating intermediate layers of soluble cellulose esters between the emulsions layers... The Gevaert Company would separate the emulsions layers by means of paraffin.... Rowland S. Potter placed a thin transparent adhesive consisting of a soap solutions... L. von Tolnay and L. von Kovodsnay applied a vacuum to bring the members into close contact. EA. Weaver would put a mild adhesive between the elements, the adhesive containing at least 60 percent glycerin... W.H. Moyse claimed to have obtained better contact by the mere expedient of surface coating the emulsion layers with a colloid... But the problem of good optical contact can be solved most easily by the use of pressure plates.. The three elements are placed between two pieces of glass of appropriate thickness, which is determined by mechanical requirements. The sandwich is then loaded into the plateholder, the back of which has heavy springs which exert considerable uniform pressure upon the glass plates. This simplest of all devices proved eminently successful and altogether sufficient to overcome any flaws that might be due to poor contact.

Now he tells me...

 

[holmburgers]

A great shot from an Agfa screen plate, found in another post but I wanted to tie it in to this screen-plate stuff.

http://seekingmichigan.org/look/2009/11/16/oldsmobile-in-pictures

 

[Máx Arnold]

So sad to see this thread dead...
I came up with the exact same idea yesterday.

Didn't you just think of printing the pattern onto clear base stickers, then sticking them to the film base and exposing through it?

I think that'd solve the registration issues (If the sticker doesn't unstick)

 

[Donald Qualls]

Sure, but it won't solve the density and coloration of the antihalation dye. Five stops of density, and usually strong coloration (magenta, cyan, etc.) which washes out in processing -- or maybe doesn't, if it's on the base side under the screen sticker rather than under the emulsion.