Recently I've been making enlarged internegs for platinum directly from
colour transparancies. The film is Tri-X and the enlarger a Zone VI with
their variable contrast head.
What I've noticed is that when I turn off the blue lamp and make the negs
using only the yellow, the grain is far less than if I were to use both or
just the blue alone. I understand how this would work with variable
contrast papers, but I'm confused by it working with a panchromatic film.
The colours in the original slides are not predominantly blue or yellow
either.
Can anyone help me by explaining this?
Thanks,
Keith.