Re: Various aspects of "grain" (was: Epson coated paper negatives)

Luis Nadeau (nadeaul@nbnet.nb.ca)
Mon, 27 Apr 1998 14:08:19 -0300

At 11:56 AM -0400 98/04/27, FotoDave wrote:
>I think we have a big misconception about the difference between traditional
>silver-gelatine negative and digital negative (this term is starting to get
>meaningless, so I mean in particular either the negative generated by
>imagesetters or by printer, that is, the image consisted of dots regardless of
>whether they overlap and produce semi-random shapes or they do not overlap and
>produce more or less like traditional screen).
>
>To think that silver negative is the same as a digital negative, only that
>silver negative has higher resolution and random pattern, is the misconception
>that I meant. And with that misconception, we have unrealistic expectation
>from digital negatives.
...

>So although both digital negatives and silver negative uses opaque materials,
>silver negative is able to give "continuous" tone light intensity, whereas
>digital negative cannot. Because dichromated colloid is hardened
>proportionally to the amount of light it received, the "continous-tone"
>negatives can give you the relief in carbon print whereas silver negative
>cannot. (Well, to be more accurate, it can, but the relief height is the same
>in highlights and in shadows, but highlight has more dots but shadows have
>less dots).

This discussion makes me wish I were in a position to rush to the lab, roll
up my sleeves and try the modern "digital" negatives. I just don't have the
time now but in a few months...

In the meantime, for the record: I have made tons of single transfer
monochrome prints and I would say that 99% don't show any relief at all...
I found that the relief depends a lot of the type of pigmented emulsion one
uses, the sensitizer, etc. What worked well for me in monochrome produced
no relief...

With the double transfer tricolor carbon the results are very different and
the relief could be "read" by someone trained to read braille.

If you are using a half-tone screen and if your pigmented emulsion is very
thin carbon *transfer* should not be necessary.

Luis Nadeau
NADEAUL@NBNET.NB.CA
Fredericton, New Brunswick, Canada
http://www3.nbnet.nb.ca/nadeaul/