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

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holmburgers

holmburgers

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Indeed! That is why it is not as appealing to me. Plus, I don't really know how I would built a plate holder with that functionality.

PE, if I leeched off some of the sensitizing dye from the b&w emulsion, what would you guess the consequence to be? Totally ruined, or no problem at all? Hopefully there is an excess(?) and thuse it won't affect it.
 

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You probably leached off the acutance dye, not the sensitizing dye. If the former, you will see loss of sharpness. Loss of either will cause light and dark streaks based on the areas which lost dye. Old films had no dyes in them for acutance.

PE
 
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Hmm, well that sounds promising. I've never heard of acutance dyes... interesting! How do they work?
 

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The silver grains and the back surface of the film can be looked at as miniature mirrors that reflect light in all directions. This reduces sharpness. An acutance dye absorbs reflections and thus increases sharpness.

PE
 
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Ahh, ok. Thanks PE, I hope that's what leeched away; I can deal with unsharp, but losing panchromaticity... not good.

Do the acutance dyes usually lie "higher" in the coating than sensitizing dyes, which I would assume are more imbedded with the silver? I'm curious to know why you suspect it is the acutance and not the sensitizing dyes.
 

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The acutance dyes are evenly distributed throughout the coating. They are intended to wash out of the coating when processed. Sensitizing dyes are adsorbed to the surface of each grain and only (generally) wash out during development or fixation.

PE
 

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I don't know if this is of use, but it might be of interest. It sounds like what you're trying to do. What is interesting is that is suggests that the screen used for taking is different to the screen used for viewing. It was taken out of the "The British Journal Almanac 1952".

I hope it helps :smile:
 

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Wow, I have never heard of the Johnson Colour Screen Process, and from 1952 no less. Very interesting, thanks for sharing! All the books I've been reading are from before that, so that explains it!

That ad raises many good ideas; namely contact printing the original panchromatic negative onto ortho film for duplication. Using a TV-screen, or even better yet, an LCD screen like R Paul has, you could reasonably ensure registration with many different negs on one screen, owing to the fact that is uses a regular grid as opposed to the Autochrome's stochastic array.

Boggy, you're becoming an asset to esoteric color experimentation :wink:
 

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Awwwww, thankyou Holmburgers :smile: If I find anything else that may be of help, I'll make sure you know first.
 
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Ok, I'm going around like a pied piper today, thanks to Boggy1 no less, but this film would make the absolute finest material for TV-screen-plates.

http://www.microcolour.com/ilfochrome.htm

With a process lens and this film on a hi-def TV or computer screen, you could probably make a screen-plate that rivals the Autochrome. Not to mention, the screen would hold its color for 500 years or more. That's one drawback of the slide-film screens, they will fade with time and when I'm an old man the colors might not be there like they are today. Not so with this Ilfochrome microfilm though. A properly processed black & white slide, toned perhaps, and a reseau of this film would be as good as permanent.

Anyways, exciting stuff...
 

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Holmburgers,
The slow speed of ilfochrome could mean that you could contact print an existing screen-plate if you get your hands on one. You could always cheat and see if you could get a digital image printed onto an ilfochrome of a screen-plate pattern. :smile:

Edit: Wow, I'm more tired than what I thought! Scrap the last part. If you get a digital print onto ilfochrome, it'd make a crappy plate because it'd be opaque.
 
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The microfilm wouldn't be opaque... it's a transparency.

Getting a réseau laser-printed onto a piece of Ilforchrome Micrographic film is actually an incredible idea.
 

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Sorry, I'm getting myself confused between paper, microfilm, and clear display film! I guess that I need to get my sleep- I'm fudging everything together and its getting messy! :redface:

I'm not sure you'll be able to get anything printed on microfilm, but I'm sure that you'll find someone somewhere that will print onto the clear display film. That'd be more or less perfect for you. The only thing I can imagine being hard to achieve is a good white balance, it might make a couple of attempts to create a good pattern. A random pattern will mean no moire, but a regular pattern could be copied from dufaycolor film. . .
 
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Here... this talks about writing digital information to the film with laser scanners - http://www.ilford.com/en/pdf/prods/micrographic/CaseStudy_English.pdf

In other news... I received 4 slide-réseau's back from the lab yesterday. I used a Wratten 6 (light yellow) filter on EPP 4x5" and the screens are very neutral; quite a good gray! The only worry is that (well, besides having finger smudges on my TV!) the green under a loupe looks rather yellow. We'll see how the result is though.
 

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That's great news! I look forward to seeing your first results! :smile:

If you find that the colour-balance is a bit off, then you could always just try using a corrective filter to compensate, a la Autochrome! :tongue:
 
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I just separated a screen from an exposed sandwich; soaking it in about 30°C water and working around the edges with my fingernails. I was able to get a really clean separation. This was the gelatin, sorbitol & photo-flo adhesive (3%, 5%, <1% respectively, IIRC) binding an Ektachrome screen to a sheet of Delta 100.

Naturally I couldn't inspect the b&w film, but the screen came out looking good with flaws only around the edges. The image area looks great; which is good because my test films got really beat up after repeated bind/unbind cycles.

The b&w film is hanging in a basket inside of a dark-bag, with gentle airflow provided through the arm holes by a small duct fan (I was particularly proud of this achievement..). I intend to reversal-process this in the near future.. just got the necessary chemicals mixed up tonight!

Something that has occurred to me is that the sorbitol, being a sugar substitute, has the tendency to crystallize. It's not very pronounced or problematic yet, but it got me thinking about ways to mitigate crystal growth. A quick 'googling of the interwebs' taught me that candy makers have the same problem. Some quotes,

+ "Interfering agents" are ingredients which prevent the growth of large crystals. For instance, when making fondant, cream of tarter is added with the sugar to produce an invert sugar which inhibits large crystals from forming.

+ Interfering agents are added which prevent the growth of large crystals or prevent crystallization such as invert sugar, which is molasses or corn syrup, and/or an acid, such a lemon juice, cream of tartar or vinegar. Even the addition of fats and egg whites coat crystals and prevent their growth.

+ One way to prevent the crystallization of sucrose in candy is to make sure that there are other types of sugar—usually, fructose and glucose—to get in the way.

+ A simple way to get other types of sugar into the mix is to "invert" the sucrose (the basic white sugar you know well) by adding an acid to the recipe.

As far as I can surmise from wikipedia, sorbitol is glucose. -> "It can be obtained by reduction of glucose, changing the aldehyde group to a hydroxyl group. "

So would the addition of table sugar, sucrose?, be effective in preventing crystallization? How about citric acid??

A really "sugary" adhesive that would be resistant to crystals sounds like an ideal adhesive; it dissolves easily, is inert and it's easy!
 
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Cool, I'll check it out. Thanks PE

EDIT: Ok, I did some looking around. It seems that bartenders are the ones most familliar with simple syrups. They are still having troubles though with it crystallizing, usually at very high concentrations (2 parts sugar, 1 part water).

In theory, given what the candymakers have said, would adding table sugar along with the sorbitol (sucrose + glucose) prevent crystals?

Man... all this photography is making me hungry!
 
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Hey there. Definitely not dead, just sleeping. I'm actually awaiting the arrival of a MOD 4x5" processor and with that I'll be able to do reversal processing finally. Turns out my deep tanks had leaks and the idea of tray processing with sulfuric acid seemed less than ideal.

I do apologize for the lack of progress. A year or more later and only one humble screen-plate... doesn't say much for my work ethic, eh? :wink: I've been doing the dye-transfer thing mostly in recent weeks, but I fully intend to get this project going as soon as I can.

Thanks for asking... you've lit a fire.
 

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My friend, I embarked on the same project almost two years ago, and you've gotten ten times farther than I have. Kudos to you.
 
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Let's Get Up To Speed...

Guru, I appreciate that, thank you.

Ok, here is some updated information regarding things that I've already done, but have thus far been poorly illustrated.

Image #1. This is the b&w positive image that was exposed under a screen-plate, developed by dr5 (Delta 100). The slide looks exponentially better in person... these digital cameras can't do justice to the brightness range in the least.

#2-3. These are my best attempts at lining up the screen with the positive and achieving the best color. One exposure favors color while the other attempts to show the range of brightness evident in person.

The reason the banana is pink is because the screen and b&w film were not flush during the exposure, making registration nearly impossible at this stage. The most realistic color can be seen in the leaves of the ______ (my roommates sleeping otherwise I'd ask him what plant it is), the white painted apple and the Budweiser coaster. Can anyone identify the book?? Reading this whole thread would probably give it away....

#4. The screen and the positive; note the scuff-mark on the screen, result of not cleaning the television very well before making the screen. The same thing happened with my most recent screens too unfortunately. Cleanliness is important! The blue hue is quite apparent in this screen, but it actually seemed to balance out tungsten illumination well. It resembles an 80a filter I think. Also note registration holes; courtesy of a 2-hole punch. The sheets are stuck emulsion to emulsion for best sharpness.

#5. My newest screens. This time I used a Wratten #6 filter (light yellow) to cancel out the blue hue of the previous TV-screen-plate. Very neutral, but under loupe the greens appear a tad yellow. Who know's, I'm excited to try these. (note scuffs on screens! aahh!)

#6. Example of extreme moiré, importance of perfect and flush registration.

#7. Examples of variability in screen neutrality. Disregard the damage on the green screen, this is due to using it as a test sheet for binding with gelatin, unbinding, etc. (it's been abused). The striking green hue is result of the LCD flat screen computer monitor used for that exposure. The back-light in these is fluorescent, discontinuous and wreaks havoc on film, particularly EPP which I think is kind of an old school slide film. Tests with E100VS proved less extreme. The blue is an unfiltered CRT TV screen, the gray ones are w/ #6 wratten filter.

The blue réseau here is awaiting development of its companion b&w positive. The damage around the edges is caused by the gelatin/sorbitol mating. Probably in large part due to fingernails and trying to get the sheets "unstuck" underwater, in complete darkness. However, I'm quite pleased since it's mostly confined to the non-image areas. I'll be lining it up with it's positive as soon as I reversal process it. Registration is likely to be excellent, but seeing as this will be my first time to ever reversal process film, the quality of the positive will be at the mercy of the darkroom gods.

#8. These are tests with E100VS and various filter combinations. I did 3 shots with each filter, +1, 0 -1. My ghetto-rigged light table doesn't have the most even illumination however. The first 18 are shots of a LCD monitor; I added magenta to them to reduce the green cast, but apparently EPP and E100VS act quite differently as nearly all of these were way too magenta. These were the filters used in chronological order. 40M, 30M, 50M, 20M, 30M+20C, No Filtration. The results may be inconclusive honestly.

Skip the one underexposed random photo (it's supposed to be a glowing stove, since I stopped to make tea while taking these damn pictures...)

The next 15 are pictures of the TV. Respectively, in groups of 3; No Filtration, #3, #6, #8N5 (I don't have just a #8), #9. I concluded that the wratten #6 was the most neutral and it seemed to translate well to EPP.
______________________________

So basically this is the current state of affairs. I still have a lot of hope for this method, and I know that one day that I'll be looking at an excellent color picture produced in this manner.

I'd encourage anyone else out there to give it a shot themselves and let's see what the world looks like through a screen-plate!
 

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i think these are great and your work is highly commendable. you will have awesome results in no time.
 
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