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.
Although silver particle is opague and although modern film has thin emulsion,
silver negative achieve tone by some suspension of the opague material in
gelatine. When light pass through the negative, it gets scattered by the
silver grains and the gelatine mix; thus when it finally comes out, the
intensity is reduced. Although not 100% correct, you can indeed think of it as
something like a 100% light shining through the film, but come out with less
intensity of, say, 50%.
A digital negative does NOT work that way. If you take an area of 50% tone, it
has 50% clear area and 50% opague area. It does not have any suspension. Thus
when light shine through this area, 50% of the area pass through all the 100%
of light, and the remaining 50% area blocks all the light. Thus the intensity
of light coming through digital negative is not altered at all. It is still
100% (I am ignoring the slight loss because of the negative's Dmin for the
purspose of this discussion). Tone modulation is achieve through the size of
the "areas" rather than actually cutting the intensity of light.
With finer resolution, the same principle still applies. If we think about the
50% area (with checker board style opague and clear area), the coarse
resolution is analogous to the size of floor tiles, the finer resolution is
like the size of a chess board, etc. etc. No matter how fine it is, it is
still 50% area passes through *all* the light, and 50% area *blocks* all the
light. (Of course, I am talking about the 50% tone area only).
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).
If now you have a printer or imagesetters that can make you a 120,000 dpi
negative, or lets exeggerate and say 1,200,000 dpi negative (assuming you have
good transparency or film to handle that, of course), you now have a negative
that you cannot tell the difference (well, in this case we should probably say
that the digital negative is better than the silver negative) from a silver
negative as far as tone is concerned because you can't see the dots even under
maybe a 100x loupe. As far as tone modulation is concerned, this is beautiful;
but as far as whether you can produce the high relief in darker area (in
carbon print), you still can't. You simply can't because it is not the case
that more or less light (or light with higher or lower intensity) passes
through the negative. It is still the same principle: in some areas, the light
gets passed through 100%, and in other areas, the light gets completely
blocked. There is no modulation in intensity of light, just modulation in
area.
If you don't believe me, take an area of a digital negative, take the 50%
area, it should reads about density 0.3. Now take some silver negative,
exposure and process to a density of 0.3. Compare the two under a loop. You
will see that the silver negative shows *crisp* or *hard* dots and it looks
completely different from the silver negative. The silver negative is not
simply the same crispy but higher resolution type of negative. It is
completely different as there is suspension of grains as I mentioned earlier.
Digital negatives are beautiful, but I just hope we understand it in its
physical level and understand how it actually works so that we won't have
unrealistic expectation from them. You should fully understand how digital
negative works and how your process works so that you can fully utilize the
combination.
(c) 1998 by David Soemarko