Re: Posterisation & burnt out highlights
Re: Posterisation & burnt out highlights
- Subject: Re: Posterisation & burnt out highlights
- From: Henrik Holmegaard <email@hidden>
- Date: Wed, 19 Sep 2001 17:52:40 +0200
Steve wrote:
This tends to whack out the target and if your profiling application
cannot apply ink limiting to the target prior to printing, then you
may be losing tons of information in the puddles and having precious
few decent patches left over.
If I may, then this is not the best way of putting it, not even today ... -:).
When you print a target, you are fingerprinting the behaviour of the
printing system. From this fingerprint, you create the profile.
As I tried to say in the January inkjet profiling ABC, if your RIP
does not apply ink limiting properly, you are going to get a target
with over-inking or under-inking. And mis-inking (to coin another
impossible phrase) affects the size and shape of the gamut.
I have seen IT8.7-3 targets with almost nil differentiation left in
the shadows, compared to neat differentiation off the HP 5KPS using
non-HP Swiss media, for instance.
What good does it do to buy a type of printing system which offers
very large gamuts for presentation printing and simulation proofing,
if the ink limiting is such that you can't get the benefit of the
gamut size? It's sort of like using Aunt Emma's 4 year old 15" Apple
Trinitron RGB as working space. I mean, honestly ...
Once the Lab measurements are pulled off the printed test chart,
warts and all, you have already lost the gamut. Sure the profile can
restrict ink, but asking it to get you good ink limiting and shadow
differentiation back is like asking for the eternal fountain of youth.
Ink limiting and black replacement in the profile is applied AFTER
the process has been calibrated to deliver the largest gamut it can.
Then you may make some changes, typically in offset to save on CMY
and to stabilize the process against color fluctuations.
I don't mean to whack any side in all this, but just to stick to common sense.