In Camera Tricolor separations, HOW?

[Kirk Fry]

Has anyone tried to make in camera color separations, scanned them and then reassembled color photos in photoshop?
So if so:
1) What filter set (25, 47B, 58) or (29, 47b, 61)?
2) Did the exposure for each filter vary and by how much?
3) What film developer combination?
4) Same development time for all 3 separations?
5) Is it easy to register the images in photoshop?
6) Did it work? And yes if stuff moves between exposures you get color fringing.

Thanks
Kirk

[mark anderson]

you might want to look into four color seperation for press work, i did a lot back in high school, but my note book fell off the buggy on the way home.

either your subject will have to be very still, or you will have to change filters very fast.

[Bill_1856]

Kirk, I haven't done it for 50 years, but it used to be standard for making Dye Transfer prints from still life. I don't remember the details, but I do remember that each film had different exposure times, and different develoment times. It was a HORRIBLE PITA.

[Dan Fromm]

Kirk, if you have in mind to shoot, e.g., landscapes in b/w and end up with color prints, and read french go here http://www.galerie-photo.info/forum/ and search for trichromie. Henri Gaud has been working at it and has got interesting results, some quite good.

[Donald Qualls]

If you watch eBay carefully for a while, you might see a tri-color camera go by. I've seen a couple, at least one in 5x7, even. These expose all three films at once, using neutral density along with the color filtration to even out exposure. Given the dense filtration needed, it's still possible to shoot living (if not genuinely action) subjects at reasonable shutter speeds by using ISO 320-400 film.

For *viewing*, it almost doesn't matter what filters you use, as long as the final images are viewed with the same filters (Autochrome, essentially tricolor on a single film or plate, used violet, green, and orange, at least early on). For *printing*, the same is true except that it's very helpful to have the filters match fairly well to the sensitivity curves of the emulsion layers in the print material, or to complement the ink or dye colors for print or transfer.

[Hal Hardy]

1) What filter set (25, 47B, 58) or (29, 47b, 61)?
2) Did the exposure for each filter vary and by how much?
4) Same development time for all 3 separations?
5) Is it easy to register the images in photoshop?

1) When I did direct screen seperations from slides in an enlarger for process printing, I used the 25/47B/58 filters. These broader cut filters were used because the overlap of colors allowed for corrections to compensate for impure color press inks. Since you're reassembling the image in the computer before you go to a printing device with hopefully cleaner color inks, I would say to use a narrow cut filter combo. With the broad cut filters, you'll end up with off color and muddy reds, greens, and blues.

2) There will be a filter factor for the exposure. If the film manufacturer doesn't have a starting point on the data sheet or reply to an inquiry, you'll have to experiment.

4) Just for giggles, I experimented with indirect (continuous tone) seperations. I tried Plus X, Tri X, and T Max 100 films. There were different development times with Plus X and Tri X, but T Max 100 had the same developing time for each color. (Don't be like me my first time- snip a different corner of each neg when you load them to tell which color is which. :o )

5) Does PS have a registration function? I got the hobby version with my scanner and haven't gone through all of its capabilities yet. When we first went digital at work, we used a Leaf Scan. It did re-registration if it was off vertically or horizontally. I never had one that was crooked so don't know if it worked for those.

The tricolor camera Mr. Qualls mentions is your best bet if you plan to do a lot of this. Unless your camera is rock solid, just changing film holders will play havoc with registration if the rear standard moves even slightly.

[Michael Heald]

Hello! If you google astrophotography, you'll see that folks were doing some amazing tricolor work with Tech Pan up to just a few years ago. The filters varied a bit as t what people wanted to do. Tech Pan had a high red sensitivity, so that had to be considered into the system as well. Best regards.

Mike

[Tracy Storer]

It's covered in David Scopick "THE GUM BICHROMATE BOOK" and In Richard Farber "HISTORIC PHOTOGRAPHIC PROCESSES" and I'm sure, many others. It's do-able, but pains-taking. A lot depends on what printing process you're using how fussy you want to be. Here's a link to a couple examples of mine:
http://www.tracystorer.com/tri_color_work.html

[Marko]

Has anyone tried to make in camera color separations, scanned them and then reassembled color photos in photoshop?
So if so:
1) What filter set (25, 47B, 58) or (29, 47b, 61)?
2) Did the exposure for each filter vary and by how much?
3) What film developer combination?
4) Same development time for all 3 separations?
5) Is it easy to register the images in photoshop?
6) Did it work? And yes if stuff moves between exposures you get color fringing.

Thanks
Kirk

Hi Kirk,

That's the exact same idea I've been thinking about for some time, but never quite got to try. So, your post finally made me do a very primitive but quick test with the equipment I have on hand.

Going down your list of questions:

1) Cokin red, green and 80A - nowhere near the ideal combination, but that's what I have.
2) For each exposure, I took an incident reading through the filter, incident light.
3) 320 TX in D76, 1:1, tray
4) Yes, same time, same agitation, one-shot chemicals.
5) Yes, it is, relatively speaking. There is a little trick to it, though, which I will describe later.
6) Sort of. The scanner and the "technique" I used with it was too imprecise for this to really matter.

1166

Since I don't have a large format film scanner, I scanned all three negatives in a reflective mode, with white paper behind them. It took a little experimentation and the results are, of course, unusable for any kind of even semi-serious work, but again, that's what I have on hand and it served the purpose of a quick experiment.

To register two layers in Photoshop, change the blending mode of the upper layer to "Difference". This will create an effect similar to positive-negative. Simply move the upper layer until you accomplish the minimal difference. Finally, turn the blending mode back to "Normal" and you are done.

Once all three layers are in precise register, copy the "red" layer into the red channel, the "green" layer into the green channel and the "blue" one into the blue channel. Delete the layers and use the Channel Mixer and curves to adjust the color balance and saturation.

For comparison, here is the regular image taken with a digicam:

1167

Regards,

Marko

[sanking]

Has anyone tried to make in camera color separations, scanned them and then reassembled color photos in photoshop?
So if so:
1) What filter set (25, 47B, 58) or (29, 47b, 61)?
2) Did the exposure for each filter vary and by how much?
3) What film developer combination?
4) Same development time for all 3 separations?
5) Is it easy to register the images in photoshop?
6) Did it work? And yes if stuff moves between exposures you get color fringing.

Thanks
Kirk

Back in the 1980s I made quite a number tri-color carbon prints, some from in-camera separations, others from separations made from 5X7 Ektachromes transparencies. For in-camera separations you want to use the 25, 47 and 58 set, for separations from slides the 29, 47b and 61. The difference between the two sets is that the band width for the second is not as wide as for the first.

I used primarily Super-XX film, which has a very long straight line curve and was one of the films recommended by Kodak for separations. Exposure for the Red and Green record were about the same, but much less for the Blue. Development was different for each of the records to produce a balanced set. I used Kodak DK-50 to develop the separations. In experimenting with a couple of other films results varied a lot, so you will obvioulsy have to experiment a lot to get this right.

It has crossed my mind to assemble some of the separation negative sets in Photoshop and while I have not done it, I don't think it would be particulary difficult to do so.

I also have a 5X7 Devin tri-color camera but one of the pellicle mirrors is torn and would have to be replaced, at $250, to put it in use. I plan to do so at some point in the future as I would like to do a project with it.

Sandy King

[Kirk Fry]

All,

Thanks, this is wonderful. So I am not completely nuts, this looks like a fun project. I am going to give it a shot. The image registration part bothered me but that seems to be doabel after scanning. In the analog days this would have been a killer. The clipping corners idea of negatives has already saved me time. Two holders, 3 separations and one with out filters.

Thanks all.

Kirk

[Donald Qualls]

Oh, damn. Registration solved.

Now I'm going to have to get some tricolor filters that will fit one of my lenses, or a Cokin-style holder.

MUCH simpler to just shoot C-41 in my Speed Graphic, but that doesn't produce silver gelatin negatives that can reasonably be expected to last into the 22nd century...

[pierre506]

The normal picture:174253

Tri-color：174254

[jnantz]

i've been making stereoscopic trichromes for a little while .. you have to cross your eyes to get the effect
and ... its worth the headache afterwards

[pierre506]

Yes，the stereo results are stunning.

[John Layton]

Kirk...you should really try contacting Jim Browning who lives in Lebanon, NH. He's a (traditional) dye-transfer guru...a seriously vanishing breed for sure! Very confident that he's among the most knowledgable tricolor separation folks alive today. At any rate...give'm a google!

[sanking]

A couple of images made from three-color separations on panchromatic film. The separations were made with a 5X7 view camera on 5X7 panchromatic film, through Red 25, Green 58 and Blue 47 filters. I originally made same size contact prints with these separations with three-color carbon, and slightly larger prints with three-color carbro.

The attached images were created by scanning the original separation negatives and assembling the color layers in Photoshop. With the use of digital controls the image quality is much better than I was able to achieve in the past, though so far I have only printed these files with an inkjet printer. However, I started to make three-color carbon prints again a couple of years ago and plan to reprint one or both of these images soon with digital separations. Many things have changed over the years, but the actual analog component of making three-color carbon prints remains a lot more challenging than just exposing and developing the separations.

Sandy

[EarlJam]

My dad was born in 1921 and came of age in the Technicolor era. He had a fascination with bi- and tri-color photography and built a two-color camera out of an old folding camera. I have one print from that camera, a picture of his younger brother, probably taken in 1938.

My dad also collected Curtis and Devin tri-color cameras, in a variety of sizes from 2.25 x 3.25 to 5 x 7. With one of the Curtis cameras was a 1948 price list which provides some details on the process. See pages 9 through 11 of the attached. Apologies for the low-ish resolution on the scan. PM me for a better copy (roughly 3 MB).

174312

174313

[Drew Wiley]

There's an old Devin tricolor camera on the conversation piece shelf of the local photo stre. It's too beat up to be worthy of restoration. The ultimate tricolor cameras were Technicolor movie cameras. But if one were shooting primarily distant subjects without a parallax issue, they could simultaeously trigger three separate small cameras precisely mounted and aligned. Some people just use three separate exposures and hope that nothing moves. If I were rich, I'd order a beamsplitter prism custom coated with neutral density plus separation color. But I'm getting too old and lazy for any of this. I do know how to make color separation negs from chromes. Maybe one of these days I'll try to make a pin-registered back for my 8X10 and try the real deal.