FotoDave@aol.com
Tue, 12 Jan 1999 18:18:56 -0500 (EST)
In a message dated 1/12/99 1:49:48 PM Pacific Standard Time,
Bob_Maxey@mtn.3com.com writes:
> Please, everyone who has an idea about this, define continuous tone.
Ok, I am going to try to define it. It's not from textbooks since most books
more or less assume silver negs as continous tone (or maybe because when the
books were written there weren't that many digital options to compare). The
definition might not be exactly right but it is for the purpose of discussion
because I do think that continous-tone negative produce effects different from
"digital" negatives even when shadowing, scattering, difration, etc. causes
continous tones in digital negatives. But that I will start the discusson in
another thread.
For the purpose of discussion, let's define a truly continous tone negative
(true contone) as a negative whose densities will cause the reduction of the
light that passes through it as if the original light is dimmed (intensity
reduced). Let's say you use a 60W bulb in your enlarger and expose a piece of
material for 10 seconds (without any negative), and expose another piece of
material with a 30W bulb for the same 10 seconds. A truly continous-tone
negative (which probably doesn't exist) with the corresponding density would
produce the same effect.
We know that our ordinary silver negs cannot do that because of grain
structure, but it is approximately continous tone because the grains are
suspended in gelatine is some finite thickness.
Let's also define a truly binary negative as a negative which has only a
perfectly clear area or an area that perfectly block out any light that passes
through it.
There are also a few terms that need clarification:
1. "digital" is a bad word when it is used in contrast to continuos tone. A
film from a film recorder is also a digital output, but it is "continous
tone." I don't have a term for "digital" negatives. Can we call it "dotted"
negatives for our discussion? (I don't want to use "screened" negative becuase
that is associated with halftone screen).
2. "silver negative" is a bad term when it is used in contrast to "digital"
negative because digital negatives from imagesetter ARE silver negatives.
Those produces with inkjet printers, laser printers are not silver negatives.
We know that continous-tone negatives are not true contone, "digital"
negatives are not true binary, so we have difficulty with terminologies. I
will use camera contone negatives as our ordinary negative processed normally
(like TMax processed in TMax according to normal instruction), agree?
Summary
=======
We now have (in the order from true continous-tone to true binary):
1. true contone
2. camera contone
3. dotted negative (imagesetter negatives, inkjet negatives, laser-printer
negatives, etc).
4. true binary
Are these terms agreeable for now? If so, I will start to ask my questions
about continuous versus "digital." Since #1 and #4 do not exist, our
discussion will be whether #2 and #3 produce the same result and when and
how....
Dave
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