Re: Printer profiles and testcharts
Re: Printer profiles and testcharts
- Subject: Re: Printer profiles and testcharts
- From: Henrik Holmegaard <email@hidden>
- Date: Wed, 4 Apr 2001 09:24:38 +0200
Per Savander <email@hidden> wrote:
There is a choice between TC2.9, TC3.5, TC6.02 for example. Is the
improvement of quality dramatic or minor if you profile an inkjet
with a 2.9 or a 3.5for example?
If somebody has already done a comprehensive and serious test of
this, please let me (and all of us) know - one test less to do !
The gurus are in India, the rest of us are in the office -:)
The manual explains which testcharts are available simply for legacy
reasons (meaning the 'hey, we always used this with PM2X so why can't
we use this now...?' kind of issues) and which testcharts are
recommended.
Testcharts take time to measure. They take time to even if you
measure them automatically. The larger the testchart the longer the
time. So all print profilers have multiple.
Print profilers also live in a world where folks hanker for
standards. That adds some more choices.
The manual says the TC6.02 is recommended. It is big, that's true,
but the point is that the patches are well spaced. The IT8.7-3 has
less well spaced patches but it is a standard unto itself.
If you are looking for a little less work, do the smaller TC3.5 which
is also good.
The assumption many have is that the mathematical representation of
the color space is built directly off the color patches. Therefore,
they reason that the more patches the better the quality. This is not
true.
You can get fine profiles with the 200 odd patches of the basic
Printopen testchart. You can get tighter profiles with the four part
extended Printopen testchart which also has patches for skintones,
for instance.
But it's debatable whether you get better profiles using the TC6.02
versus IT8.7-3 in ProfileMaker or the four part extended testchart
versus the IT8.7-3 in Printopen.
If you use the recommended large testcharts in ProfileMaker and
Printopen, you will get good results.
But you will only get good results if you know how to use a
spectrophotometer. Once you have the print profiler and the right
testchart, the rest is a matter of sound measuring practices.
--
Henrik Holmegaard
TechWrite, Denmark