Message
Re: [colorvision_group] Re: dual monitors
2007-01-23 by CDTobie@aol.com
In a message dated 1/23/07 10:48:23 AM, rhill3@... writes:
David, I decided to try a test to see if I could confirm that each
monitor is indeed being loaded with a different profile
But thats the wrong question, and the reason so many people are deceived by this issue. The OS does not load a profile, it just makes it available to applications. On Windows it does not load videocard corrections either, unless a utility makes that call. This utility should be making it, but does it flash it uniquely, and successsfully, for each monitor?
and that it
is the one assigned to it using the WinColor applet.
After booting the machine, I used the applet to assign a profile to
the secondary monitor which caused the monitor to produce a very dark
image. I set it as the default for the monitor.
That would be the video correction for one or the other monitor (assumedly the correct one) being applied to that monitor. If this works right, it should remain looking just like this thereafter...
I then rebooted the machine. During the boot sequence, the
appearance of the monitors changed as follows:
1. Shortly after the desktop appeared, both monitors changed to what
I am assuming is a no profile state.
How do you assume that? We have to assign obviously wrong, and obviously different, LUT data to both monitors to determine when one, the other, or none, is being applied...
2. Later, the appearance changed to what I know both monitors look
like with the profile for the primary monitor applied.
No profile is being applied to the monitors, VLUT calibration data is being applied.
I would guess
this is Win XP or the NVidia driver applying the same profile to both
monitors which is the expected behavior since I have a single video
card.
Applying the same LUT data (as I would expect) to both monitors... wrong data to at least one of them at that point.
3. At the very end of the boot sequence, the secondary monitor
changes appearanceto what matches the dark profile I assinged to it
using the WinColor applet.
So now different LUT data is being used for each. Thats half the battle.
The primary monitor does not change.
This, to me says that the applet has loaded a different profile and
applied it to the one monitor but not to the other.
But will applications like Photoshop actually get the different (and correct) profiles assigned for both monitors as well. VLUT calibration data is still only half the battle...
I have the
applet in my startup folder with the "/L" parameter so that it runs
with no input required.
I do not know what the applet is doing, but it does appear to be
applying separate profiles to the monitors.
We'll assume its assigning the profiles for the monitors (for application use) as well as utilizing the VLUT data from them. But you would have to prove this by seeing that each is using a seperate profile in Photoshop or some other application to be sure its all working.
In my case, I built the
profiles using the Spyder2 and gave each a unique name based on the
monitor type, I have assigned these profiles as the default profile
for each monitor using the WinColor applet in interactive mode.
For the record, my video card is an NVidia Quadro FX 3400. My
primary monitor is an IBM C220P CRT and the secondary is a Dell
1905FP.
Is there something else you would like me to check to help answer the
question about whether or not the applet is applying the unique set
of corrections to each monitor?
Short of sending you monitor profiles with clearly wrong profile descriptions, and ones with clearly wrong LUT data, so you can confirm whats what, there isn't much more you can check the way you're doing it. Sounds promising though; let me know, off list, if you are interested in getting such profiles from me...
C. David Tobie
Product Technology Manager
ColorVision Business Unit
Datacolor Inc.
CDTobie@...
www.colorvision.com