SR Research EyeLink 1000 Installation Manual page 46

The camera (either the Standard EyeLink 1000 Camera or the Fiber Optic Camera) mounts to
the top of the bracket using a clamp knob (M8 thread) and a set of dimples on its front. This
ensures that the camera cannot vibrate independently of the illuminator. The camera also has
5 mounting holes on its sides: 2 near the center of the camera's sides, and 3 aligned with the
optical center of the lens and sensor. These holes take a standard 1/4"-20 screw (used on
tripod and camera mounts). However, the hole at the lens end of the camera may not be robust
enough to mount the camera with the illuminator bracket attached, especially if vibration is
present.
It is recommended that the illuminator bracket be mounted to the head restraint assembly
using the 3 holes supplied near the camera mount. The long side of the bracket should be
oriented away from the subject to maximize head clearance. Once the bracket is mounted, the
illuminator and camera may be attached and re-oriented as required. The camera may be
installed with the lens on the left or right side of the bracket, and the illuminator fitted as
required to place the connector on the side opposite the camera lens. The EyeLink
configuration files may be modified to flip the camera image as required to match any mirrors
or orientation of the camera.
While the camera will accept most C-mount lenses, the performance of most lenses is rather
poor in infrared, with blurry or dark images resulting from lens coatings or non-optimal design.
The Standard Camera configuration uses a 25 mm focal length lens, selected for high
resolution and excellent IR performance. A similar 16 mm focal length lens is available which
will allow the camera to function properly when closer to the eye.
As with other EyeLink 1000 mounting options, the camera requires 12V power, and a supplied
60 mm (24") cable is connected from the camera to power the illuminator module. A supplied
ferrite choke on this cable must be on the end near the camera. Finally, a high-speed camera
cable is connected from the back of the camera to the tracker Host PC.
To summarize the above points, when installing the primate system please keep the following
points in mind:
The camera should not be too close to the eye, as the pupil and corneal reflection must
be contained within the tracking window.
Bringing the illuminator closer to the eye will reduce noise but may cause discomfort
and increase pupil erosion by the corneal reflection.
Placing the illuminator too far from the eye will result in a dark image and noisy data.
The line from the illuminator to the eye should be at least 10° off axis from the camera
lens for proper imaging.
The illuminator should be attached to a robust metal support, as should the camera.
Preventing separate motion of the camera and illuminator due to vibration is critical to
prevent extraneous noise in the data. The metal will also help to keep the illuminator
cool, increasing its light output.
38 Primate Mount Installation
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