Setting up the eyetracker
Start by making sure the subject is comfortably seated. For most remote systems height and distance are critical, so you will have to make sure the subject is in the right location. The hi-speed eye tracker is mounted on a table that's height adjustable. Make sure the seat is set to a comfortable height first, and then adjust the height of the table. The hi-speed also has an adjustable chin rest.
When the subject is in position you first need to make sure that you are getting a clear picture from the camera. The picture should be in focus and the eye should be in the center of the image and should be well lid without shadows of the eyelids on the eye. Make sure to verify that the picture is good while the subject is looking at all four corners of the screen, not just the middle. If an area of the eye picture causes problems the part of the picture that is used for eye tracking can be reduced. This works just like resizing a window.
It is important to always have a good look at the actual eye image that the camera sees to verify that the pupil is clearly visible and that the eye tracker is working properly. The RED eye tracker will only show a very crude representation of the eyes, just two ellipses, which is only good to see if the subject is positioned properly. Another window, showing the actual eye image, can be opened, and this is highly recommended, even if you think everything is fine. The SMI eye image will show an outline around the area that is interpreted as the pupil, and the area that is seen as the corneal reflection. Both these areas will also have cross-lines through them. This makes it very easy to see if the eye is being tracked properly. Ask your participant to look at all 4 corners of the screen while you inspect the eye image, as problems will ususally only show up with extreme eye angles.
With the high-speed tracker, you should ask your subject to look straight ahead for a few seconds while you click the 'auto adjust' button. This ensures that the amplifiers for the two eyes (or two halves of the image in monocular tracking) are balanced.