Re: Of a wish for Pshop 7
Re: Of a wish for Pshop 7
- Subject: Re: Of a wish for Pshop 7
- From: Henrik Holmegaard <email@hidden>
- Date: Sun, 1 Jul 2001 23:25:48 +0200
The issue in the post has to do with the current craze for converting
with relative colorimetric from RGB working space into CMYK
simulation and default output space.
This is not a safe conversion, because if Black Point Compensation is
not checked, the difference between the RGB working space black and
the black of the CMYK space is clipped. For paper type 3 lightweight
coated magazine stock you clip 15 steps of detail. For newsprint you
clip 40 steps of detail. Meaning all detail goes to black. Relative
Colorimetric with Black Point Compensation makes the black point
relative and more shadow detail is preserved. Perceptual maintains
detail and contrasts even in massive compression contexts.
If I do so, the preview looks terrible - all over a white cast. I can't
believe that this is your opinion of how a preview should look like.
I'm not sure it makes sense to ask what a preview 'should' look like.
There is no one way it should look because black looks different on
different papers.
Yesterday I bought four sheets of stiff black card. The card is
uncoated and while black it looks light black. The Eye-One measures
it at L 23. The Eye-One Share software shows it a light black. Why
should the screen look a lighter black than the actual black I
measured and that my eyes tell me is a light black? Like you I like
deep and rich blacks, but if I can't get them, why make myself
believe I can?
The default soft proof transform to the monitor should be relative
colorimetric with absolute black point. This way the lighter black of
the printed page is light on the monitor, too. The default soft proof
in Photoshop is relative colorimetric with relative black point
('Black Point Compensation') which creates shadows as deep as the
monitor is capable of. This is fine when targetting colors for a
presentation printer with a black point of L 4 and a white point of L
97.5, almost the same as the black and white of my CRT. But it leads
to disappointment to map offset shadows relatively to the deepest
black of the monitor.