Color separations of color film images

[alanrockwood]

I have a question. Suppose I have some color films that have been developed (Kodachrome, old versions of Kodacolor, old versions of ektachrome, E6, C41, etc.) Does anyone consider making color separation negatives of those images? It may sound like crazy-talk, but here is why I ask. Color images have limited stability. It seems to me that making color separation negatives would be one way to make more archival version of those images. One might consider making color separation reversals as well, so the black and white reversal images would have the same sense (positive or negative) as the originals.

Of course, there would be plenty of technical and practical problems to overcome, but let's discuss the idea and the issues. For example, in order to minimize degradation of the quality of the images in the reproduction process it might be a good idea to step up at least one format increment when making the color separations... for example making color separations of 35mm images onto 120 size film.

 

[Anon Ymous]

Perhaps a contact copy would be a better approach. Emulsion to emulsion.

 

[138S]

Making color separations from color film (https://en.wikipedia.org/wiki/Separation_masters ) is (or was) the gold standard in the movie industry for long ter preservation, there is extensive documentation about this.

Kodak sells color separation film "KODAK Panchromatic Separation Film 2238" https://www.kodak.com/uploadedfiles...ost_Production/Archival_Films/2238_TI2404.pdf

which is the ideal tool for that, it is low ISO to outresolve the camera film.

Anyway let me suggest you another way, a frost-free refrigetator:

http://cool.conservation-us.org/byauth/messier/negrmcc.html
http://www.wilhelm-research.com/pdf/HW_Book_19_of_20_HiRes_v1c.pdf

Even in the case you make color separations, I'd store valuable color film properly, regular room tempreature is not good.

Perhaps a contact copy would be a better approach. Emulsion to emulsion.

The color separations for preservation are also contact copies (emulsion to emulsion), usually.

 

[Kino]

You would need a means of registering the RGB copy images, either mechanical or optical.

If money is no object, you could find a Nikon F body (F1 thru 3 I believe) with the Oxberry pin-registered backs that were used in slide copying systems and have a mechanical registration in the camera.

Otherwise, you'd need to rig a punch and pin system like the old Acme and Oxberry animation systems, which brings size into issue.

It all depends on what you want to copy and how you intend to recombine the images at a later date.

It would take some real work and testing to be sure of results.

 

[Bob Carnie]

That is what colour Gum printers and Carbon printers are doing, separating original negs into three or four silver friends and then registering them back and making permanent prints. I have done upwards of a thousand tri colour gums to date.

 

[Kino]

That is what colour Gum printers and Carbon printers are doing, separating original negs into three or four silver friends and then registering them back and making permanent prints. I have done upwards of a thousand tri colour gums to date.

No doubt!

It all depends on the volume and format of what you intend to copy, as well as the provision you will have for recombining the records at a later date.

Myself, If I was just doing a handful of images, the system for tri color gum prints would probably be the best route if it were a large format color original. If you want to do emulsion to emulsion contact copies of a 35mm slide, that's a different story.

Personally, if I were copying a sizeable quantity of color 35mm slides, I'd take the slight image degradation of optical copying. I'd rig a slide copying system with a good 1:1 macro lens, RGB color wheel and use Kodak 2234 panchromatic dupe neg stock in a pin registered movie camera. While you can contact copy continuous strips of 35mm film emulsion to emulsion fairly easy, copying one image three times in register would be a nightmare and would require some serious machine tool work.

You could do a similar thing with a medium format camera, shooting some slow speed panchromatic stock, bellows and copy lens and put optical registration markers in the frame to be used in recombining.

 

[cmacd123]

the movie folks do have their images on film with BH Perforations which as slightly smaller then KS perforations found in the still world, so three passes through a contact printer to make the three separations should not have too much misregistration. still 35mm would be slightly harder to make the three copies.

I believe the special films that were used to do dye transfer prints are long gone. there the three separation negatives were all done in a pin registered Jug, and I belive thet the separations were the actual size of the eventual print.

On the Movie side --> 2238 would be the separation negative stock, but it looks like they only make it in 35mm

 

[gordrob]

In dye transfer once the separation negatives were made they were normally enlarged on to the matrix film. A 4x5 separation negative for example could be enlarged to whatever size the printer wanted on the matrix film and the resulting matrices were then dyed and rolled out to give the final print. Contact dye prints could also be made depending on the size of the original negative or transparency.

 

[138S]

the movie folks do have their images on film with BH Perforations which as slightly smaller then KS perforations found in the still world, so three passes through a contact printer to make the three separations should not have too much misregistration. still 35mm would be slightly harder to make the three copies.

I believe the special films that were used to do dye transfer prints are long gone. there the three separation negatives were all done in a pin registered Jug, and I belive thet the separations were the actual size of the eventual print.

On the Movie side --> 2238 would be the separation negative stock, but it looks like they only make it in 35mm

Perhaps I is not necessary to massively register a full collection of 35mm negatives, if a convenient registering system for that specific work is not found (custom build KS/BH?), if in the future the information has to be rescued probably it would be done digitally, as RA-4 optic printing is not frequent, so Photoshop (of what used) will align BW separated images easily.

Anyway the separated frames can be aligned and registered in the future (with a bino loupe and micro geared shifts) when needed and for those frames needed.

 

[DREW WILEY]

This takes specialized gear and quite a bit of testing and experience to do well, which also equates to a firm financial commitment. Plenty of people fool around with so-so fun methods, which is fine; but quality separations really have to be pre-matched to the specific printing or repro application in mind, and this requires some expertise. Old literature won't help you much because films etc have changed. TMax 100 is a very good separation film.