09-08-2020, 12:20 PM
This issue is usually caused by not using the "Search Limits" feature, or by setting the limits too large. When enabled, the Search Limits feature create a red ellipse on the camera image, telling the Host PC to only search for an eye within that specific area, This prevents the Host software from accidentally locking onto the other eye after head movements, and helps reduce the likelihood of other parts of the image being mistaken for an eye (e.g. nostrils / glasses).
How to enable and use Search Limits
You should make the ellipse just large enough to comfortably contain the participant's eye.
Important: Never make the search ellipse smaller than the green square that it encloses. Doing so will interfere with the tracker's ability to follow the eye as it rotates.
How to enable and use Search Limits
- Enable the Feature: On the Host PC, go to the Set Options screen and click the "Use Search Limits" button. A red ellipse will appear on the camera image.
- Position the Ellipse: Center the red ellipse over the eye you want to track. You can do this in two ways:
- Mouse: Simply click on the desired location in the eye image.
- Keyboard: Hold the Shift key and use the arrow keys (←↑↓→) for precise positioning.
- Mouse: Simply click on the desired location in the eye image.
You should make the ellipse just large enough to comfortably contain the participant's eye.
- To adjust the size: Hold the Alt key and use the arrow keys (←↑↓→) to change the horizontal and vertical dimensions of the ellipse.
Important: Never make the search ellipse smaller than the green square that it encloses. Doing so will interfere with the tracker's ability to follow the eye as it rotates.