Cinematoraphy Quasar Tube Photometrics

Thảo luận trong 'ENGLISH' bắt đầu bởi Matthew Jeppsen - DP, 25/1/18.

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  1. [​IMG]Quasar Science Q-LED tubes have a very popular new lighting option, but oddly enough Quasar doesn’t offer any photometric output data on their website.

    So after hearing this question far too many times, I finally put a meter on my standard 4′ Quasar Q-LED crossfade tubes. I’ll update this post in a few weeks with photometrics on the 2′ crossfades, and the 4′ switched bi-color versions as well. Quasar has new RGB models as well, but the crossfade and bi-color models are most widely available at present.

    The 4-foot crossfades have a color temperature dial that ranges from 6000k to 2000k. I metered a single 4-foot tube in footcandles at 6000, 4800, and 2000 kelvin settings at distances ranging from 1ft up to 12ft from the fixture. Crossfades seem to deliver the most output at the daylight end of the spectrum. Here are my results:

    @ 6000 kelvin
    1ft – 320fc
    3ft – 90fc
    6ft – 30fc
    12ft – 11fc

    @ 4800 kelvin
    1ft – 300fc
    3ft – 84fc
    6ft – 26fc
    12ft – 10fc

    @ 2000 kelvin
    1ft – 190fc
    3ft – 52fc
    6ft – 16fc
    12ft – 6fc

    And for folks interested in modifying Kino Flo fixtures with Quasar tubes, Rob Macey provides the following photometrics on six LED tubes in a 4×4 Kino shell at 10ft distance: f5.6 @ 640 ASA. That’s about 60 footcandles on subject, almost twice the output of a standard Kino flourescent 4×4.


    5.6 @ 10ft (640 metered)
    6 Quasars in a 4' Kino pic.twitter.com/Xr1kET7Y3d

    — Rob Macey (@macey_rob) July 12, 2017

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