Calibration of Dual Monitors does not work !

Hi there,

although I bought 2 “equal” ViewSonic 24" monitors, there are slight differences, which I can’t compensate with the monitors setup.
Thus I thought I 'll do it in OS13.1’s SytemSettings/Hardware/Display and Monitor/Gamma. But although the display configuration is able to see that there are 2 monitors attached, th Gamma config. Screen selection is grayed out - I can’t select a screen and calibrate it.

To my surprise the calibration tool is also not working on both screens. Every change is only displayed on the 2. screen …

For me that sounds like abug.

Anyone here had a similar problem … and maybe a solution ?

I tried to checked and unchecked the sync screens option several times, but the only differnce is a hook appearing and disappearing; it seems to have no other effect. Changes made to the calibration are still only used for the 2.screen.

TIA for your replies,


What video card and what driver?

Oh and what desktop??

Excellent questions. Desktop is probably KDE, as the OP mentions system-settings.

In my system - KDE 4.12 oS 13.2 Nvidia, dual monitors (DVI + HDMI), colour calibration/correction can be done per screen with nvidia-settings, not in system-settings, which sees both monitors as one long screen.

AFAIU the OP misconception - and mine too, for some time - is that the X sees two screens, when what happens is that the video driver join both in one screen with two displays, and this one double-width/double height/extended screen is what X, and consequently the desktop, sees.

There are, or were, ways to configure X to see two screens, as opposed to two displays. Xinerama, or xorg.conf editing, or such. It’s been years since I looked into this, as it just works with my setup, so no certainties here.

Except, obviously, for the facility positioning and switching the displays on/off.

Hmm, on second thought, this is probably BS. It would depend both on the driver programmer exposing the settings to the display manager developer, and this one implementing it for that specific board/driver. Kscreen settings may work for open source drivers, for instance.