09-08-2020, 12:30 PM
The question marks indicate that the tracker was unable to identify the optimal threshold values during the auto-threshold process, and is instead using the last accepted values. This can often be due to something interfering with tracking at the moment of the auto-threshold (e.g., a blink or eye-movement). Try performing another auto-threshold, making sure that the participant is looking straight forward and keeping their eyes open, or simply adjust the thresholds manually, using the ↑ and ↓ arrow keys for the Pupil threshold and the "+" and "-" keys for the Corneal Reflection threshold.
If the threshold values are high (i.e. Corneal Reflection values above 230) or low (i.e. Pupil value less than 75) after performing an auto-threshold try to decrease or increase the illuminator power, respectively, and perform auto-threshold / manual adjustment again.
The auto-threshold function is intended to find Pupil and CR threshold values that are close to an acceptable range, but the thresholds should always be adjusted manually to achieve the optimal values. Please see the following thread for detailed instructions on adjusting thresholds to their optimal values.
If the threshold values are high (i.e. Corneal Reflection values above 230) or low (i.e. Pupil value less than 75) after performing an auto-threshold try to decrease or increase the illuminator power, respectively, and perform auto-threshold / manual adjustment again.
The auto-threshold function is intended to find Pupil and CR threshold values that are close to an acceptable range, but the thresholds should always be adjusted manually to achieve the optimal values. Please see the following thread for detailed instructions on adjusting thresholds to their optimal values.