I've been doing some interesting tests with digital negatives recently
and I can now definitely recommend halftone linescreens rather than the
diffusion dither bitmaps recommended by Dan Burkholder. They print much
smoother, especially useful for broad monotone areas.
On a more interesting note however, I have noticed that it appears that my
prints from these digital negs are composed of more than just the black
haltone dots. This is very strange, and I don't understand it so I was
hoping someone else might have some insight. Let me elaborate...
I take my digital neg which is composed entirely of clear dots in an
appropriate pattern. I would expect that, when looked at with a loupe,
the final print would look like just a bunch of black dots. However,
what I find is that it actually looks like someone exposed the paper to a
continous tone negative which laid down swatches of tone (but no detail)
and then printed the black dots on top of that. Weird. My father, who
has been working in the printing industry for 35 years confirmed what I saw.
As a specific example, those of you that double-coat you paper know what
it's like when part of the image prints on an area that has just a single
coat. The single-coated area prints a stop or two darker than the
surrounding double-coated part. Well, suppose this occurs in a broad area
of continous tone, such as a sky. If you look at the transition between
the two with a loupe, the halftone dots are exactly the same size in both
the single and double-coated areas, but the smooth, continous tone
*background* is darker in the single-coated area. Now to my way of
thinking there should be no "background" just the halftone dots. This
seems to occur in the normal print area as well, and is *not* related to
the single/double coating.
So, what's going on? Is my digital neg acting as both a continous tone
neg and a digital one at the same time somehow.
Stanger than fiction,
David