Color separation negs from slide. Is it possible?

[Perry Way]

Hello, I'd like to take some of my 4x5's (slides, E6's, chromes, color positives, whichever you call them) and make color separation negatives from them (enlarged actually) so I can do 4 color gum printing. I have a color head on my Omega enlarger. Is that color head only useful for printing color positives using color negative film? Is it possible to make RGB (Red Green Blue) negatives with what I have? I'm thinking I could use the enlarger, yes, but I'd have to find me some RGB filters to do the separations. If making these negs is possible then this is the route I want to go down because it's a two step process (enlarge & color separate, print) to the final print rather than three steps (enlarge & color separate, reversal, print) starting with a color negative original. Please go easy on me. While I'm not known to be color blind, I am kind of color dumb.

 

[Ian Grant]

You just need to buy a set of Tri-colour separation filers. Wratten no's 25 Red, 58 Green and 47 Blue. There's also a stronger set usually termed Deep, 29 Red, 61 Deep Green and 47b Deep Blue

These filters originated in the early 1900's at Wratten & Wainright in the UK who where early pioneers of Panchromatic emulsion, Kodak wanted Mees their photo-chemist to head up a new Kodak Research facility and the deal was they also had to buy the company.

The Dye transfer sites will have details on making the actual separation negatives from transparencies.

Ian

 

[Ian Grant]

Kodak have discontinued most of these particular Wratten filters.

Ian

 

[Perry Way]

This site has a downloadable pdf on dye transfer printing that includes a section on making separation negatives.

Awesome! I will read this now! I have looked high and low on this topic, not saying I'm all that or that Google isn't all that, but I could not find anything except how to make digital color separation negs. Well shoot.. I knew that digital route years ago, but honestly at this point I am not interested in the digital route. Too costly (the hardware required to do this myself) and quality not as good.

 

[Photo Engineer]

Perry;

Go to Jim Browning's dye transfer web site for a good discussion of this process and making Dye Transfer prints.

At Kodak, we used the WR98, 99 and 70 filters for our separation negatives.

PE

 

[Akki14]

I think we should point out that even with the filters you'll probably have to work with panchromatic film, not safelight safe ortho film, yes? Because ortho film won't react the same way as panchro to the colours...

 

[sanking]

I think we should point out that even with the filters you'll probably have to work with panchromatic film, not safelight safe ortho film, yes? Because ortho film won't react the same way as panchro to the colours...

That is correct. Only panchromatic film can be used for color separations, and the best film for this purpose is one that has a long, straight line curve. I would recommend TMAX-100.

I made many color separation sets from Ektachrome transparencies in the 1980s. At the time Kodak literature recommended the narrow band filter set Red 29, Green 60, and Blue 47b for separating transparencies, and Red 25, Green 58 and Blue 47 for making separations from life.

Sandy King

 

[Loris Medici]

Sandy, doesn't Tmax 100 has a UV blocking layer? I think the O.P. was planning to use the separations for gum printing...

 

[2F/2F]

The color head on your enlarger should be set to 0 for all three filters for this particular chore. When you are separating an original positive, you need to filter using the primary colors of light, not their compliments.

Do the named separation sets (I count three of them made by posters in this thread) account for the fact that enlarger lamps are warm in color?

 

[Photo Engineer]

I tested one of the new Kodak B&W films, I think it was Tmax 100, but not sure. The wedge spectrogram indicated that it did have a UV absorber. I wish I could remember which film it was! Another film had the UV absorber omitted. This information is available on Kodak's web site though.

PE

 

[Ian Grant]

I tested one of the new Kodak B&W films, I think it was Tmax 100, but not sure. The wedge spectrogram indicated that it did have a UV absorber. I wish I could remember which film it was! Another film had the UV absorber omitted. This information is available on Kodak's web site though.

PE

Tmax 400 sheet film has no UV barrier. See Kodak's PDF.

I think the 100 does.

Ian

 

[Photo Engineer]

Thanks Ian. I could not remember as it was a few years back.

This implies that other films in that family do have the UV filter then?

PE

 

[Ian Grant]

Yes, 35mm Tmax 400 has the UV blocker as well as all the Tmax 100. Sandy King could add more to this regarding other films.

Ian

 

[Perry Way]

Wow, some good information here! And now I'm feeling some regrets because I shot a LOT of slides this winter/spring. This is a lot of work and sounds expensive maybe too expensive for me at the moment because I can't guarantee 100% darkness in my room with my enlarger so I that I could use panchromatic film.

Like just about everything I do in life I lunge forward with a cavalier spirit and then suffer the ramifications afterwards. Kind of like "The Fool" in the tarot deck, one foot on the ground, the other hanging over the edge of the cliff, and a little dog making a ruckus trying to keep the fool from taking the next step. Even the dog is wary, but the fool, he doesn't have a care in the wind, and he doesn't even recognize the warnings from the dog even.

I want to gum print some of these slides so much, but I lack the funds to do this the right way, right now. So either I have to wait, or possibly I could find someone who would make the internegs for me, for a fee of course. And of course for a select few slides. I know Stephen Frizza could do these for me, but that's all the way over on the other side of the world. Does anyone know of a more local resource (I'm in California)?

 

[holmburgers]

Perhaps I'm missing something, but it doesn't seem like this should cost much. If you can find the sep filters for cheap on eBay, that's probably the greatest cost. I don't know much about gum printing by my understanding was that it's pretty cheap. 4 sheets of film, process, etc., chump change to a darkroomist. Get some black plastic or foil tape and you can be light-tight in no time.

Unless your time is money, GO FOR IT

 

[Perry Way]

The color head on your enlarger should be set to 0 for all three filters for this particular chore. When you are separating an original positive, you need to filter using the primary colors of light, not their compliments.

Do the named separation sets (I count three of them made by posters in this thread) account for the fact that enlarger lamps are warm in color?

Oh that's a very good question 2F! Thanks for thinking of that! I think that my enlarger (Omega D5XL with dichroic head) has a halogen bulb, though not having the need yet to replace it I don't know for sure. A quick peruse of Google indicates that halogen bulbs can be warm or cold, but the most abundant is warm bulbs. I detect more research is necessary!

 

[Perry Way]

Perhaps I'm missing something, but it doesn't seem like this should cost much. If you can find the sep filters for cheap on eBay, that's probably the greatest cost. I don't know much about gum printing by my understanding was that it's pretty cheap. 4 sheets of film, process, etc., chump change to a darkroomist. Get some black plastic or foil tape and you can be light-tight in no time.

Unless your time is money, GO FOR IT

Making the room where my enlarger is, light tight, is the least costly of the things I need to do. My first calculations at cost to produce my own negatives assumed I could use ortho film and that I could also use my color head to dial in filter values. Yellow + Cyan for green, etc. But in the last few days I started looking for wratten filters and first thing I found is I can't find them all but the ones I have found are costly. I bought a 45 filter auction for dirt cheep, getting 45 wratten filters but only one of them is on the list of filters people have suggested above. Secondly, I can't find panchromatic film of the size I want to enlarge to. I am certain that if I could find that size it would be enormously expensive by comparison to ortho film. Maybe I have to buy a roll and cut it down? Okay, so if I do that now I have to buy the roll holder, the radial cutter or whatever you call that device. There are costs in here that make it prohibitive for me to do this myself (at this time). I don't particularly consider a minimum of $500 as "chump change".

 

[holmburgers]

Oh, well I guess I was imagining 4x5" film, but indeed if you are doing some ULF stuff then you know what you're talking about.

On filters... I'd look for gels or cellophane filters. Often times people are clearing out a huge lot of 20+ gel filters and the seller won't even list what filters are there. You have to message them just to get the list and this extra step results in a lot less auction competition.

P.S. I have no idea why I'm getting double words sometimes, this just happened on another post... it's always the first line, last word. WEIRD!

 

[holmburgers]

Just had a thought... you could make in-camera separation negs w/ panchro 4x5" and then you could use ortho for the enlarging process. Granted, you'd be introducing another optical step and thus a loss of resolution, but since it's for a gum print I'm guessing you wouldn't notice. Might simplify things?

 

[Photo Engineer]

There are some very nice tri-color cameras that are or were available on EBay and other sites. Some of the guys on the yahoo dye transfer forum use these cameras for the original image and do as said by Holmburgers.

You cannot use CC filters for making separations, as the CC filters never reach the cutoff value that true Wratten separation filters do.

PE

 

[Mainecoonmaniac]

Here's a cheats way. It done digitally. The neg is made from this ink jet transparency material. Mr. Burkholder prints platinum and other alternative processes this way.

Good luck!

http://www.danburkholder.com/Pages/main_pages/page1_main.htm