Rips
Rips
- Subject: Rips
- From: "DuWayne" <email@hidden>
- Date: Tue, 17 Sep 2002 17:05:07 -0400
>
As with all calculated data with interpolation and interpretation there are
and will
>
be some errors dependant on precision.
Its old legacy code that's the killer - a few dozen decimal places to our
monster processors is no big deal.
>
Hmmm. Linearisation puts the printer in a balanced repeatable fashion, a
>
known state if you like.
It assumes that the printer is not in a repeatable fashion. This isn't true
because Heidelberg tested Epson & Roland's over months when developing
proofing systems and found that they vary by .40 & .35 delta E. Even in a
very controlled environment too may other factors came into play like the
spectrophotometer precision is +-.25 Delta E.
If you assume that the printer will drift due to other factors -
environment, media coating etc... to a state that you don't like. You must
also acknowledge that you have the possibility of hue & chrome shifts which
linearisation will not correct. So you might as well build a new profile.
>
>Gamut by proper linearisation is increased not decreased. When too much
ink is laid down at a certain >>point the Chroma values reverse. Trick is to
maximize the gamut by linearisation, something that the >>Epson drivers
didn't have.
I understand what you mean but try it in the real world. Linearise the
Epson driver and then apply a transfer curve to your patch target in
Photoshop and build profiles. Your gamut will fall apart. Inkjet inks don't
respond in a linear fashion and its the light inks that really cause the
problems. I know the guys at Bestcolor really well, when they do a baseline
linearisation there gamut shrinks a lot --which is great for them because
they are trying to get to swop.
Download Profilemaker demo and use their gamut viewer in profile editor.
Look at all the canned profile that you can download for all the rips in the
market that do linearisation and compare them to ImagePrint's canned
profiles. The gamma differences are huge.
>
>What does the actual separation of the LC, LM (Blacks in the case of the
>
>Epson Ultrachromes) then?
Its pure software control - you can do anything you want anyway you want.
4,5,6,7 colors your choice. This is the difficult part - there are an
extreme number of combinations. Pick a color like dark red - what inks do
you use
1) CMY
2) MYK
3) MYGRAY
4) CMYlclm
5) MYLcLmK
6) MYLcLmGray etc.....
Now once you choose your inks what percentages of each because a lot of
combinations will make the same color but will give you other problems like
to much liquid.
All the hardware is capable of printing a lot better than we have ever
seen - its the software control that the problem. The light colors &
variable dot technology make every resolution on each printer a big project.
It used to be easy to write a driver for the 4 color and even 6 color
printers - you got close and all the resolutions printed pretty good. The
variable dot 7/8 colors machines are require lots of time. Roland just
released 5 new machines -- 6 heads 12 cartridges 300 sqft per hour last week
Its going to be 3 new drivers for a whole new type of head. Epson has the
10600 with 6 color ultrachrome. The rip developers just don't have enough
qualified bodies to write the code from scratch - so the rig it. Well you
can only rig it some much till you get trapped- that where a lot of rips are
like onyx, colorburst etc...
The realty is that the manufacturers don't care - they don't want to you to
print perfect- more ink -- more paper -- less development costs. There not
going to sell more printers if they spends a $100,000 on making the driver
perfect - only a few people care and its less paper less ink sales.
DuWayne Rocus
Omniscience, Inc
South Florida Roland Dealer
(954) 584-2949 (954) 316-4841 Fax
www.rolandmedia.com
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.
- Follow-Ups:
- Re: Rips
- From: Graeme Gill <email@hidden>