Stimuli Luminance

You can measure the luminance values of your stimuli using the SpyderX Pro colorimeter which can be found in the storage cupboard in MF-B447. Follow the steps below to measure the luminance:

1. Open DisplayCAL on the stimulus monitor.
2. Plug the SpyderX Pro colorimeter in the participant monitor (you might have to unplug e.g. the keyboard to make space), and turn the light on in the experimental room on the same brightness as you would during the experiment.
3. In DisplayCAL the SpyderX will already be selected. Check that the 'Mode' is on "LCD White LED" and that the correct 'Display' is selected (XG258 = Researcher, XG248Q = Participant).
4. Click on the button "Calibrate & profile" at the bottom of the screen.
5. Click on "start measurement".
6. You will now see the pop-up to self-calibrate. Leave the light-tight cap on the instrument and click on "ok".
7. You will now see the pop-up to place the instrument on the test window. Remove the light-tight cap and place the colorimeter (with the camera-side) on the grey box.
8. Keep the colorimeter on the box (keep pressure against the screen during the
   measurement with a chinrest for example), click on "ok" and afterwards (after the pop-up left) click on "Start measurement".
9. The box will turn white, and values will appear. You can now move the colorimeter to face the stimulus you
   want to measure. When the value for "Current" is stable click on "Stop measurement" to freeze the luminance values.