Damien Symonds

Standard.

Well yeah, better talk to X-Rite.

Goes to show how much the computer's graphics card effects the calibration.

You were calibrating the desktop screen attached to the laptop, yes?

Poor in what way?

Are you still there, @Michelle G?

How did it go?

To avoid colour shifts, I use Ctrl-Shift-U to desaturate the layer before running the filter on it.

There's lots of mind-blowing stuff in the Channel Mixer class. The second one is definitely better. But of course it's not finished yet. Go ahead and commence your normal Levels work on it, the same way you'd do for any black-and-white photo.

Gosh, good job! Now add an overall Channel Mixer layer, hit the "Monochrome" box, and enter +100/0/0/0 for the values.

Of course, best in the world. But you've come this far, maybe you should try it, at least?

Oh! That's DVI, not VGA. That's absolutely fine. But you'll need a hdmi-to-hdmi cable to test your screen with your laptop.

Keep trying. It's REALLY important that you have no VGA pins involved in this.

So you had a cable that was hdmi at both ends?

Oh shit!!!!!! Ok, that might explain a lot. Is there a HDMI port in the back of your computer? Your real computer, I mean.

That's right. Then go to the Display Settings control panel and make sure the it's set to "Extend":

Great.

Remember, the assessment of colours must only be done in a colour-managed program. So if you don't have Photoshop on the laptop, you'll need to install Bridge.

It's ok, that will work. Plug your desktop screen into the laptop computer and calibrate it there. See if the same magenta problem exists. I should have asked this sooner - what kind of cable is connecting your screen to your computer?

Ok, it's time to do some tests. Do you have another screen you can plug in to the computer and calibrate? If that was high in magenta too, it would point to a graphics card issue.

Ok, good.

Ok, this scares me: You have to find that setting in the screen's menu and make sure it is turned off.

Is it this monitor?

Yeah, that's fine.

This one? https://www.asus.com/sg/Monitors/ML239H/