Color seperation question

[Robert Kennedy]

I have a question about color seperation.

Now, if I am looking to do a gum print, I can do it in 3 or 4 passes using the CYM or CYMK method. A layer for Cyan, a layer for Magenta, etc.

Fine and dandy.

My question is this...

For reasons of sheer "doability", it looks like digital negs are the way to go. Much better control. I know, nasty stuff, but what choice does one have besides making 3 or 4 in camera shots with filters?

Doing some research, I found Sam Wang's article on Unblinking Eye ( http://unblinkingeye.com/Articles/3CG/3cg.html )

Nice, but confusing. It seems you invert the image and then make a neg from each layer. Fine, but I'm not sure how this works out in real life? It LOOKS like Photoshop inverts all the colors. The Wang talks about opposite colors and my head starts to spin. Color theory is something I am not big on. Any insights here?

 

[rc3]

I just started to work with Sam's method and have made one good print. I invert the image and then split channels and have a gray scale for RGB. Red=Cyan,Green=Magenta and blue=yellow. I put about six coats of yellow and red layers over the cyanatype. Need to find a better red for the one I am using is to red/orange. With a true red color correction would would take less effort and layers. Since I am new to gum printing I am going through different pigments and how they work with the gum.

So Sam's article is a good starting point, just a matter of time finding the right combinations of pigment layers and exospore for each layer.

Best Regards,
Robert

 

[rc3]

I just uploaded a small scan of a work print of the tri-color gum to my photo gallery.

 

[jantman]

What's wrong with making 3 or 4 in-camera negatives? SOme photographers were still shooting separations in the 70's and early 80's, and that's all they did before that (for the really good work).

I've never worked in color separations, but all it is is making three or four identical negs but with different filters. Granted, with subjects which aren't totally stationary it might be a bit of a problem (unless you want to build a custom camera) but it's doable.

Oh, also, I guess this is what should come to mind first, since it was the method used up until (relatively) recently when the press world went digital:
You shoot regular color film and then, in the darkroom, make (contact or enlarged) separations from the original neg.