PWM dimming on SP4?

Discussion in 'Microsoft Surface Pro 4' started by Zybane, Nov 1, 2015.

?

PWM dimming shown?

  1. Yes

    1 vote(s)
    100.0%
  2. No

    0 vote(s)
    0.0%
  1. Zybane

    Zybane New Member

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    Does anyone know if the new SP4 uses pulse width modulation (PWM) to dim the screen? This can cause eye-strain for some people like me. PWM is a cheap/crappy way to control the brightness of a display.

    You can do a test here:

    Blur Busters UFO Motion Tests

    Focus on the moving vertical lines with the SP4 at 40% brightness or below. Is the moving line one "solid" blur or can you see any separate lines within the blur?

    If it is the latter, there is PWM dimming.
     
  2. Zybane

    Zybane New Member

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    To help, this is what the difference would look like. Stationary (notice line on right):

    [​IMG]

    Moving without PWM:
    [​IMG]

    Moving with PWM:
    [​IMG]
     
  3. the_new_normal

    the_new_normal Member

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    Great question which I'd love to see an answer to
     
  4. Charlie Cassidy

    Charlie Cassidy Member

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    PWM is not a "cheap, crappy" way to dim LEDs. It is the standard way to do this. LEDs do not have much of a curve when it comes to brightness vs current.
     
  5. Zybane

    Zybane New Member

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    I've been in the monitor business for a long time. PWM is precisely a cheap and crappy way to dim an LCD screen. Why do you think so many manufacturers are now touting PWM/Flicker free monitors? Direct DC control and steady voltage changes is a far better method, but costs more.

    People go to great lengths to test and record which are flicker free:

    Flicker Free Monitor Database

    For a new device going into 2016 with PWM dimming it's a very poor design decision. Since it appears no one wants to do this simple test and confirm either way, I'll have to order a SPro4 to test myself. Guess what; if it has PWM it's getting returned.
     

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