[argyllcms] Re: Can we control the shadows (was black point compensation)
- From: Graeme Gill <graeme@xxxxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Tue, 17 Dec 2019 11:02:57 +1100
Refik Telhan (Redacted sender rtelhan for DMARC) wrote:
Hi,
Using a UV filter (or the M2 measurement mode) does not make the
FWA/OBA-related
problems go away. It is just a simple way of “ignoring” their presence.
Ignoring for the purposes of measurement, but not useful for profiling
since the UV is (typically) not filtered out when viewed.
The lighting industry by laying UV to rest has already depracated the
FWAs/OBAs.
The vendor of the Sun doesn't seem to have got that memo though :-)
None
of the recent LED light sources have a UV component. Even the Violet Chip,
Red, Green,
Blue Phosphor LEDs start emitting from 405 nm, while blue-chip LEDs start
from around
430 nm).
There is still a lot of non-LED lighting out there, and the graphic arts
industry seems to have rolled out a lot of viewing booths with carefully
set UV levels.
IMHO, until the day paper industry replaces these chemicals with
non-fluorescent white
pigments, the best practice would be to “ignore” them by using the M2 mode,
if and when
you cannot “avoid” the use of high-OBA papers.
Only if your viewing conditions have lighting with no UV. Otherwise
it will give poor results with FWA containing paper.
The printing industry has already lost to much time and energy on trying to
solve a
problem that has already become part of history.
I don't think that's true, because you can't eliminate all light sources
that contain UV. The problem would be eliminated if paper didn't use
FWA, but that's very unlikely as it is an effective way of making cheap paper
look whiter.
Cheers,
Graeme Gill.
Other related posts:
