Re: curves and gum and Christopher James book
OK but with making the digital negative for monochrome prints "linear" is what I want. If I want to do any tone-mapping using advanced algorithms in 32-bit HDR I'll apply that to my RAW negative in Camera Raw or perhaps the camera manufacturer will build the algorithm into the next model of Leica camera (the M10 due out in 2062) ;^) and I'll select it as an effect from a menu. That's what the technology outlined earlier in that paper is destined to be used for. It's interesting but well beyond the need of a reflected print. A transmissive positive...perhaps. (Now you've got me thinking about that Jeff Wall guy again. Maybe he's onto something. Urrrg.!) I really think it's an apples an oranges argument.
~m On Mon, Mar 10, 2008 at 8:29 PM, Yves Gauvreau < gauvreau-yves@cgocable.ca> wrote:
Michael,
this idea of custom ICC profile is excellent, it
would solve quite a few problems except one. Because prints in general have less
dynamic range then your originals, someone as to decide which part or
parts of the original range will have to be sacrificed or more positively
which will need to be enhanced somewhere in the workflow. Basically it's tone
mapping again. Suppose this profile maker exist, then with experience someone
could learn how to prepare each original to get the best out of it when printed.
I suspect that those using current methods do exactly that knowingly or
intuitively but they attribute this to the method instead of their
experience unfortunatly.
Regards
Yves
----- Original Message -----
Sent: Monday, March 10, 2008 5:00
PM
Subject: Re: curves and gum and
Christopher James book
Yes. It should be inverted. But you have to note which "mode"
the curve window is in. If you give a handful of curves a quick glance they
may look the same. You have to REALLY pay attention to the curve mode being
used to display the curve. A curve calculated for graphic mode (applied to a
positive) will, on the surface, look exactly the same as a curve applied to a
negative -- BUT since PDN users generally work in binary mode it is this
change of mode which functions to invert the curve. In the end the
effect is generally the same. Ink (read: density) is diverted via the curve
toward the dark-mid tones and print shadows in the negative to compensate for
printer's ink profile. When someone figures out how to take a curve and
programmatically graft it onto a custom ICC profile life will becomes much
simpler for digital negative "curvers" because it'll become as simple as
selecting a paper in the print dialogue. ~m
On Mon, Mar 10, 2008 at 1:09 PM, Henry Rattle < henry.rattle@ntlworld.com>
wrote:
Michael – you are right, of course. But my question
was more about – shouldn't a curve that you apply to a positive, curve in
the opposite direction from one you app ly to a negative?
David's
curve, like mine, has the shadows in the bottom left
corner.
H.
On 10/3/08 18:44, "Michael Koch-Schulte" <michael@mondotrasho.ca> wrote:
Henry, it all depends how the curve data was
gathered in the first place. Neither is right or wrong it's more a matter
of workflow. I choose to apply my curv es to the positive because I'm
taking my readings from a developed positive. I also like to work in PS
with the curve putting my highlights in the bottom left corner using the
graphic scale of 0-100 rather than the binary scale of 0-255. The
important t hing is that you apply the curve to the image at the correct
stage of the procedure. Dan Burkholder started doing it this, I also do it
this way. It intuitive for me. Others apply the curve to the negative.
However one thing puzzles me - there's a note
alongside the curve which says
"Note from David: The curve is applied
before inversion to a negative and
the image should be
RGB."
Henry
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