The camera center’s supply cabinet is the junk table of the internet. Finding good stuff among all the bad stuff means sifting, seemingly randomly, through what is presented. Naturally, the novice seeks answers from presumed experts – the foruatti. What makes them an expert? Their say-so.
What they say they know, and what they show they know are the significant elements of your risk.
Seeing in Colors
Because they don’t know what they’re talking about, they don’t see what they’re looking at.
A topic search about ‘tricolor’ turned up a discussion on a large forum. One of the posters remarked that they’d seen something interesting on ebay. They, nicely, posted a link which I followed. One of the high post pontificators pointed out that: “it is broken. Can’t work. I know because.” He didn’t know, but he deflected people. I suppose that he would rather be heard than to say something useful, or meaningful.
It doesn’t always work out. In this case it did. The box of goodies had come from a shop that did direct separations. The extras thrown in (because the seller wanted them gone) included filters, inspector guides, things from a working pre-press shop. Most of the things that anyone interested in making direct seps would need. Did the large forum braggart even look at the link? Did he even think?
In the picture on the left [‘two size tabs], we see what seems a typical 4×5 film holder. Except, when looking at it edge on, there is a ‘green’ edge, as well as a ‘silver’ back (instead of another slide). The other set of pictures show the elements of this ‘Green’ separation holder. The back slide discloses a platen, pressure-plate that holds the film toward, and against the separation filter (this one is green). You can also notice the notches for coding the separation negative. Those two ‘v’ cutouts would make 2 dark edge marks onto the film. After developing, you would see these on the edge of the film and know which separation this sheet was. Each color has a different notch code.
Direct seps are made with: 25, 58, 47 filters. These are inclusive enough to capture most of the colors of an outdoor scene. They’re available new from several manufacturers. 2020 prices range from $17 each, to $180 each. If you are still forming ideas, and gaining skills, go for the Lee’s (the lower price filters.)
Terms – refs
Direct separation; camera-separation; in-camera sep; tricolor — these are the same thing. None of them require us use RGB. Most of the examples you see will be those. If you are making dye transfer prints, these are assumed in the directions and example literature. BUT. they are not required. Any filter ‘separates’ — it is up to you to determine if there is meaning for you.
For further, very old, but worthwhile see this: 1916 Manual
Websites go offline – books are always offline. The book I’d suggest you reference is Spencer’s “Color Photography in Practice” [use “colour” to find more copies. ~ $4]
This is just a pencil, not a paint by number set.
If you do more, I’ll write more.