If you wanna tell people that what they want is not what they get because
they always have the wrong monitor, the wrong lamp with the wrong CRI, the
wrong colorimeter etc, go ahead. I prefer to say that color management was
never designed to give people decent color in their own uncontrolled
environment, even though the technology could be leveraged for that purpose.
Edmund
On Sun, Dec 15, 2019 at 12:13 AM Neil Woodall <vidsurfr@xxxxxxxxx> wrote:
That’s not necessarily true. The eye will adapt to the viewing environment
if it has a high CRI. A lot of LED and fluorescent lights do not, so that
can be a problem. However, if you want the eye to adapt, then you need to
create a white border around the print. Hanging a frameless print on a
color wall is never going to look right.
The D65 monitor is required if you are using sRGB or display P3. The icc
color matching is responsible for getting that translated to the printer
color space.
What can be more of an issue is if someone is viewing a monitor at high
brightness in a dim or dark environment. They will end up with a print with
crushed blacks because that’s not the viewing environment of the standard.
Another issue I’ve run into recently for OLED is that the brightness
changes with the APL. This means that most test patterns that are used to
calibrate the gamma end up causing you to calibrating to the wrong gamma
because the dark patterns have a lower APL that bright patterns. So you
need to be very careful calibrating an OLED monitor or TV. If you can
generate constant APL test patterns, and note that even though there is an
APL setting for calman those are not constant APL text patterns, then be
sure to use the smallest window size you can to minimize the problem.
On Dec 14, 2019, at 6:56 AM, edmund ronald <edmundronald@xxxxxxxxx> wrote:
When I started out using color management, it was accepted that you could
get good screen-to-print matches easily in closed loop in-house systems.
Industry ICC work practices create an “industry-wide” in-house environment
which is very unlike consumer viewing, so consumers have no reason to be
happy with devices and prints set up for that environment.
I don’t think a print made for D50 viewing is going to look good viewed in
a home in the evening, and it certainly wont look like a D65 monitor in
that light.
Edmund
On Sat, Dec 14, 2019 at 2:28 AM Neil Woodall <vidsurfr@xxxxxxxxx> wrote:
Sorry for the late reply.
Yes, there is research. But I think most of it is not done very well
because if the eye adapts to an emissive display differently, then I would
expect to see a size effect. That is, how much chromatic adaptation is done
is based on size of the reflective background and the emissive display. The
color appearance models (CIECAM97, 02, 16) are all based on using a 2
degree stimulus surrounded by another 10 degrees of background (as I read
the documents, that would make the background a 22 degree diameter extent
with a 2 degree diameter stimulus in the center. There is also reference to
the background optionally having a small (in the drawings 2 degree) white
point reference.
The other aspect is that there is not a physiological explanation for why
you would see an emissive display different than reflective. I would think
that the human visual system process correcting for illumination is a low
level, that is before you do object recognition, and you would need to
recognize the object to decide that it’s emissive. So I’m not sure how you
justify what they are finding.
The final aspect is that if you are doing the study, the base line should
be the reference content creation environment for sRGB, rec709, etc… and
that should require no adjustment to get a natural looking gray. However,
all of the studies seem to have the ignored this aspect and find a
different value so the ability to directly translate their findings to
specific adjustments to the display or ambient light is problematic.
I work with mobile phone companies to calibrate their displays and that
also means providing an adjustment for color temperature. They all seem to
target an adjustment that is approximately a 50:50 blend of the actual
ambient color temperature and D65. If you need to work with a display that
is not in the viewing environment specified by the standard, then I would
do this much of an adjustment
This is a link to one of the better studies.
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-3-2855
On Nov 10, 2019, at 7:17 PM, johan@xxxxxx wrote:doesn’t adapt to a emissive display the same way as it does to a reflective
Neil> There is also research that suggests that the human visual system
print.
topic. Neil, do you have any reference to the research that you referred to
I have followed this discussion and I think it is a very interesting
?
Johan
