====== SR Research EyeLink Calibration  ======
This page documents calibration steps after finishing [[hardware:eyetracking:eyelink:taskpc_setup|camera and PC setup]]

===== Calibration Software =====
Run ''control64.exe'' on the **task** PC. This will display calibration points to the participant and talk to the EyeLink Host PC.  The [[:hardware:eyetracking:eyelink:task_integration|EyeLink SDK]] installs this to
 ''C:\Program Files (x86)\SR Research\EyeLink\SampleExample\''. For prisma computers, this is likely an icon on the desktop. For an example, see [[:hardware:eyetracking:eyelink:taskpc_setup#prisma_1|Task PC Setup's Prisma1 instructions]]. 

===== Calibration Steps =====
See [[#resources]] below for details, esp. {{hardware:eyetracking:eyelink:eye_tracking_manual_2024_-_mr.docx|Parr Manual}},[[https://youtu.be/9OX7HXJEVkU?t=94|youtube]]. Briefly

  - Check focus
  - Auto-threshold
  - Adjust as needed
     * Blue is confined to pupil 
     * CR fills but no smearing
  - Calibrate and optionally validate
    * Use mouse on EyeLink Host PC or
    * From presenting computer keyboard shortcuts with **CAVAO**
      - **c**  start calibration start (show center dot)
      - **a**  auto trigger. will not advance if no tracking
      - **v**  start validate -- does not change calibration, only checks
      - **a**  auto trigger validation points.
      - **o**  exit out of calibration. Alternatively, **Escape** and/or **Control+c**

==== Changing number of points ====

If tracking is poor, presenting fewer points may be useful. 
Consider using 5 points and then 3 if calibration is still failing. <wrap alert> This will result in less precise eye tracking -- but noisy data is better than no data</wrap>

From the **Set Options** menu, at the top of the screen, click the **Calibration Type** with the desired number of points.
[[https://www.sr-research.com/support/attachment.php?aid=2751#page=43|2.4.3.2 Set Options Screen Main Functions]]

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==== Reference images ====
{{hardware:eyetracking:eyelink:pasted:20241027-170755.png}}


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===== Resources =====

Calibration is documented in many places

  * Dr. Parr's {{ hardware:eyetracking:eyelink:eye_tracking_manual_2024_-_mr.docx|Eye Tracking Manual}}
  * SR Research's {{ hardware:eyetracking:eyelink:20240903_srresearch-eyelink_el1000plus_usermanual_1.0.21_gop.pdf |EyeLink1000Plus User Manual}}
    * also on [[https://www.sr-research.com/support/thread-173.html|SRR support thread 173]]
  * SRR's [[https://youtu.be/9OX7HXJEVkU?t=94|participant setup video]] (notes for focus, CR+Pupil threshold, calibration)
    * [[https://youtu.be/28bnCAlL8lE?list=PLOdF-B36TwspxRQeam0u5Yd29wOjUWcel|trouble shooting video]]
  * [[https://www.sr-research.com/support/thread-7821.html|official forum post on calibration]]