Michael - you can go to Chris Burkett's website to see illustration of his equip protocol. For those of
us who did high-end Ciba work (or any advanced color enlarging for that matter), precision glass
carriers are an absolute must. Chris interchanges precision registration carriers into a common base
on the Durst, each carrier suited to a different mask. It's a lot like working with separation negs in
dye transfer printing. His enlarger with this kind of system was probably close to seven figures to
purchase. I have a little different system, mostly custom made, and a little different protocol for
skinning the cat, but have since moved on to experimenting with color negs, since Ciba is in demise.
For my own work I solicited samples of AN glass from all over the world (not many choices now).
This kind of work is a lot more involved than simple black-and-white printing, and one simply cannot
cut the corners. Some of these kinds of neg carriers would run four to six thousand dollars apiece.
And you can't just find them used, even if bargains sometimes come up on Durst enlargers themselves. Of course, anyone with some machinists skills could simply make one in this day and
age of CNC etc. With patience I could do it simply with a basic industrial drill press. The trick was
to find the right kind of glass - different AN pattern behave differently with different focal length
lenses, different lens designs, different film grain (dye cloud vs silver particle etc). .. a little more
forgiving with 8x10 because there is less magnification of the minutiae, of course.