SR Research EyeLink Portable Duo User Manual page 57

camera case to the Display monitor and update all sections of the "Screen
Settings" configuration tool ("Camera-to-Screen Distance" section in
particular; see section 5.4 of the EyeLink Portable Duo Installation Guide).
This step is very important for the head movement compensation when
recording the eye position data in the Remote Mode.
3) The eye-tracking unit should be aligned with the horizontal center of the
monitor. For maximum eye tracking range, the unit should be raised so that
the top of the unit is parallel with, and as close as possible to, the lower
edge of the visible part of the monitor without blocking the participant's view
of the screen. To keep the viewing distance relatively constant throughout a
recording session, a comfortable, high-backed, stable chair for the
participant is recommended.
4) Start the Host PC application. Check whether it displays "Remote" at the top
of the Setup screen. If not, click the "Operating Mode" panel in the top-left
corner of the screen and choose the Remote Mode option.
5) A camera image should now be displayed in the global view of Setup screen.
Ask the participant to be seated. Adjust the height of the chair so that the
participant is comfortable and his/her line of sight is aligned to the top 25%
of the screen. Adjust your eye tracker position so that the eye to be tracked
appears in the center of the global camera view (see Figure 3-4).
6) Now continue with instructions in section 3.2.2.3 "Participant Setup in the
Remote Mode".
3.2.2.2 Eye Tracker Setup with a Laptop Mount
Take the following steps if the eye tracker is mounted on a Laptop Mount.
1) Please make sure you use a height-adjustable chair so that you can
raise/lower the participant to the appropriate height. When the subject is
seated, tilt the screen of the laptop so that it is perpendicular to the
participant's line of sight.
2) Place the laptop mount over the keyboard area of the laptop with the two
side rails resting on the edges of the laptop. You can slide the mount
forward if the camera is blocking the participant's view at the bottom of the
screen; otherwise, the camera should be placed as close to the screen as
possible without blocking the participant's view. Adjust the position of the
laptop so that the eye tracker is placed at a distance of about 45 cm if
measuring from the front of the unit to the participant's eyes. The camera is
recessed about 7 cm behind the front of the enclosure, and the ideal eye-to-
camera distance is about 52 cm.
An EyeLink Portable Duo Tutorial: Running an Experiment
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