Eyetracker, custom calibration coordinates?


I am running an experiment including an EyeLink 1000 set up and a touch screen.
Due to the physical size of the touch screen, it is very difficult to find a spot for the eyetracker, where it is not in the way and overlapping the screen too much, while still not being too far off the side the make tracking impossible.
As I am only using a fairly small part in the middle of the screen, I am wondering if I can set up my calibration and validation routines to use custom coordinates for the presented locations? If so I can simply have the eyetracker in front of the screen, and only calibrate for the part of the screen that I an actually using for the experiment.
Hope that makes sense!

Hi there - according to this post, it should be possible to modify the grid. I’ve done this before on the EyeLink Host PC side by modifying the relevant *.INI files with multipliers between 0 and 1 that shrink the grid.

hi @jtseng
Thanks a lot for the reply!
I reply on the linked post to see if there is a solution from within PsychoPy but otherwise I might try and look at the .ini files and see if I can figure that out

For anyone running into the same issue:
It is very easy to go into the .ini files on the EyeLink pc and adjust scaling value such that you only calibrate and validate a smaller portion of the screen.
You are looking for a file called CALIBR.ini in the exe directory. Scroll about a third down the page and there will be a total of 4 lines you can edit, relating to the scaling of calibration and validation coordinates.

Hi @skjoldan
Im trying to change the calibration grid to a smaller portion of the screen. Could you maybe explain to me how to get to those .ini files in the EyeLink pc? And which lines of code i should edit to scale the grid?

Thank you!

Hi @JuanaAC
If your setup is anything like the one i used, open the eyelink pc, but rathing than booting with their custom OS, boot with windows (or other OS?), and navigate to the EyeLink files through the file explorer, you will find the CALIBR.ini file there
hope that helps!

1 Like