Multi-Display computer systems
Datacolor expert Oliver Mews gives tips on color management. Today: what is important to calibrate more than two monitors on one computer.
You need to know a little bit about using two screens on a single graphic card in your computer:
Color management systems like Spyder5 are creating an ICC profile. This profile will be handled in two parts. This first and smaller part is the white point correction which is used by all your installed applications if they can. The second and bigger part will be flashed to the LUT (look up table) of your graphic card. This part corrects the gamma, so it linearizes your primary colors (RGB).
To calibrate and use two screens on one system, you need a graphic card with two separate lookup-tables. But this exists only on real „Dual-Head“ grapic cards or if you have two separate graphic cards in your system.
Newer mid range or even better graphic cards are having separate LUT for all provided monitor connection ports. Some cheaper graphic cards are having the conntectors to use two screens, but they only have one LUT, so a calibration (and correction) of both screens is impossible due to this limitation. But you can still calibrate one screen and use the second (uncalibrated) to put you tools and pallets on.
If you graphic card has two (or more) separate LUTs can not be seen from the outside, you should ask your vendor or the manufacturer of your graphic card.