User manual

When the last calibration target has been presented, the calibration will be

evaluated. At the bottom of the Calibration screen, each eye's calibration is

graded and displayed as follows:

GOOD (green background): No obvious problems found with the data

FAILED: (red background): Could not use data, calibration must be repeated

The background color of the message indicates the usability of the calibration.

We must still validate the accuracy of the calibration: only serious problems can

be detected here. If problems are found, examine the pattern formed by the

pupil-position cursors (arrays of crosses) for misplaced or missing fixations. If

the calibration was successful, you may press the “Accept” button or the ↵ key

to accept the calibration results. Pressing the “Restart” button or the ‘ESC’ key

will restart the calibration. Pressing ‘ESC’ twice exits to the Camera Setup

screen.

Some users (especially the programmers in the phase of testing experiment

programs) may want to run calibration and validation with mouse simulation.

To do this, first delete all of the "M*.cal" files in the “C:\ELCL\EXE” directory of

the Host PC. Start the EyeLink program, set the "Tracking" option as "Mouse

simulation". Go to the Camera Setup screen, type 'C'. This will bring up the

calibration screen. Press the space bar only once to initiate the calibration

process. One cross will be immediately printed on the screen. In addition, the

calibration target and the mouse cursor move to a second calibration point.

Press the left mouse button on the Host PC. Click the left mouse cursor for all

of the following calibration targets, until the calibration finishes.

The Status Panel reports the current status for pupil, corneal-reflection, and

target (EyeLink Remote only) signals and thus will indicate any lapses in

collecting data. In normal operation, the indicators are green. Should any of the

indicators display a color other than green, there is a problem with the setup

that must be addressed to prevent data loss.

Indicates Status of CR-Pupil

OK = Pupil is visible

SIZE = Pupil is too large

MISSING = Pupil is missing

The pupil status error message “SIZE”, highlighted in yellow, indicates that the

size of the pupil is too large or too small. This should not occur when the

camera is mounted on the EyeLink 1000 Tower as the camera to eye distance

has been carefully calculated to ensure compatibility with a wide range of

different pupil sizes. For the EyeLink Remote, the pupil “SIZE” warning typically

suggests that the pupil size is too small because of the ambient lighting or the

eye tracker is placed too far away from the subject.

72 An EyeLink 1000 Tutorial: Running an Experiment