Re: Photoshop 6 and odd CMYK values
Re: Photoshop 6 and odd CMYK values
- Subject: Re: Photoshop 6 and odd CMYK values
- From: Martin Andersson <email@hidden>
- Date: Thu, 24 Jan 2002 11:05:44 +0100
Thanks for your replies, but the problem isn't solved,
Steven Hwang <email@hidden> wrote:
>
I tested with PrintOpen 3.0 to creare print profile. Below is my setting.
>
1. Black generation / GCR Amount 100%
>
2. UCR - Under Color removal / Total dot ares: 400%; Maximum black: 100%
>
You can get RGB(255,255,255)--->CMYK(0,0,0,0)
This does not apply to my version of PO4 or the output profiles on the PO4
CD. I know there are some Heidelberg people on this list, any thoughts?
Henrik Holmegaard <email@hidden> wrote:
>
PS6 uses the right PCS encoding with 'Adobe CMM' selected, but that doesn't
mean the profiles you are chaining also use the right encoding.
A peek into the 'B2A1' and 'B2A0' LUT of the actual profile:
100.3906, 0.1445, 0.1445 --> 0.0000, 0.0000, 0.0000, 0.0000
'Although the 16-bit encoding can represent values slightly greater than
100.0, these are not valid PCS L* values and they should not be used.'
(ICC.1:1998-09 p.83)
But,
'.. technically L can never be higher than 100.0. However, in the case of
B2A1 tables (or any other B2A kind of table), it is ok and actually expected
that 100.3906 have an entry in the table. It's just understood that these
rows are designed to deal with erroneously high values.'
(DuPont, Checking for Problems in ICC Profiles and ColorSync CMMs, p.14)
Once again I looked into the 'B2A1' LUT of an in Sweden well known generic
newspaper profile 'fargpressen_v2.icm' (ProfileMaker version: 30c6000):
100.3906, -0.0039, -0.0039 --> 0.1282, 0.0610, 0.0671, 0.0000
Guess what, using the same setup in PS6 previews 1,1,1,0.
>
if you are using ProfileMaker then update to v315 or v4.
And what if I'm using PrintOpen 4? Couldn't find any update on Heidelbergs
crappy website. (crappy means: do not present any real and useful
information at all)
Chris Cox <email@hidden> wrote:
>
The biggest problem is that you're using the Apple CMM instead of the Adobe
(ACE) CMM.
No, now I quote myself: 'Engine: Adobe ACE / Apple CMM (same result)'. In
Color Scientist I only used 'Apple CMM' for well known reasons.
/Martin Andersson
----------------------------
Martin Andersson
Malmv Centraltryckeri
email@hidden