Home Forums Eye Tracking Devices IR LEDs wavelength?

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  • #3572
    Masta Lomaster
    Participant

    Hello,

    A friend of mine lives with ALS and tries to use Tobii devices (Rex and EyeX and two more from other vendors) to control a computer.
    Unfortunately he wears strong aspherical glasses and the devices does not work properly: lose the eyes all the time and do not give the right gaze position.
    I am going to order a custom coating for the glass lenses to get rid of parasitic glints. So I need to know the exact wavelength of the infra-red lights you use in EyeX and Rex.

    Please give me the numbers.

    Thank you in advance.
    Mikhail a.k.a. Masta-Lomaster.

    #3580
    Masta Lomaster
    Participant

    I found the article stating that “The centre wavelength is 850nm with bandwidth less than ± 30nm”
    http://www.tobii.com/en/eye-tracking-research/global/support-and-downloads/faqs/501a0000000jYSr/

    But this was true in 2012. It seems like the newer EyeX device has LEDs with shorter wavelength (one can easily see the red light).

    Can you please provide me the precise wavelengths for the Rex and EyeX?
    Thank you.

    #3582
    Jenny [Tobii]
    Participant

    Hi Mikhail,

    As far as I know we are using that wavelength in all Tobii eye trackers. What we have done on the EyeX is that we have three red LEDs that shine more intensely than the near infrared illuminators to “cover” the flickering of the illuminators. The eyes will not perceive the flickering as disturbing this way.

    #3583
    Masta Lomaster
    Participant

    Hi Jenny,

    Thank you for your prompt help and for demystifying the Red Lights of the EyeX.
    Much appreciated.

    Mikhail.

    #3736
    Martin Kopecek
    Participant

    Hi Jenny,
    Is it some development possibility to use some filter for the red wavelength for EyeS…? Or some other hardware possibility? How looks like the commercial devices? Also the same intensity and wavelength of light? Intensity of sensor is to high and it is really disturbing after few minutes of working. I understand that IR of higher wavelength can be unhealthy…but this is really annoying.

    Thank you, regards Martin

    #4622
    Martin Kopecek
    Participant

    Hello,
    Is it some development possibility to use some filter for the red wavelength for EyeS…? Or some other hardware possibility? How looks like the commercial devices? Also the same intensity and wavelength of light? Intensity of sensor is to high and it is really disturbing after few minutes of working. I understand that IR of higher wavelength can be unhealthy…but this is really annoying.

    Thank you, regards Martin

    #5936
    Alexandre
    Participant

    http://www.tobii.com/en/eye-tracking-research/global/support-and-downloads/faqs/501a0000000jYSr/

    Unfortunately I could not access the content. Someone have current links?

    #5942
    Grant [Tobii]
    Keymaster

    The original information is still valid today in 2016 for the EyeX that the centre wavelength is 850nm with bandwidth less than ± 30nm

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