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Thread: LED Panels and Television cameras

  1. #1
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    Default LED Panels and Television cameras

    Hi Guys

    Is anyone out there involved in the TV broadcast industry / I've been asked to supply some LED panels for a TV show backdrop and floor area.

    Does anyone know of the implications on flicker interference between leds and the digital cameras ?

    Any info would be appreciated.

    Thanks

    Fluff
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  2. #2
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    My friend is in this line of work, I've just sent him a text, I'll let you know.
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    Doc's website

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  3. #3
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    We hire IP6 and IP10 LED panels for good prices.
    Right now we have nearly 200 square metres
    If anyone interested, just give us shout.

    I will find out for you those implications as well.

  4. #4
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    I have just spoken to my friend about this and the answer is yes, the camera settings have to be tuned to eliminate the flicker.
    http://img62.imageshack.us/img62/3985/laser.gif

    Doc's website

    The Health and Safety Act 1971

    Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.





  5. #5
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    Thanks Doc.

    Can you ask you friend about rgb led lighting and frame rates on a camera ? I need to make sure I'm not quoting an unusable product. Is pulse width modulation a problem? Whats the best type of led dimming/mixing to use with cameras ?

    Sorry for all the questions. I appreciate the advice. Thanks.

    Fluff
    The light at the end of the tunnel. Its' a white laser.
    www.rocknite.co.uk

  6. #6
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    Back in my day we used to use gen lock for this. Gen lock syncs all of the refresh rates to a master clock so monitors and projectors don't get out of phase with each other or the cam. I don't know how the modern digital stuff deals with this. I would imagine there is still some kind of master ref for the studio.

    Are the led panels serving video? If so then I would imagine that you want to gen lock the video server to the house. If they are running stand alone then you need to bring one down and let the cam guys play with shutter speeds to find something that doesn't create harmonics.

    chad

    *edit- Sorry just re read your last post. Looks like you are using just rgb lighting. He is probably going to just have to play with shutter speed and exposure. You might have to stick with high color saturation. In other words colors at full or close to full so the pwm is minimal.

    You will also be surprised just how much key (or white) light they use for talent. Chances are that there will be so much light on set that you have to run your led stuff at full any way.
    Last edited by chad; 08-19-2009 at 21:11.


    When the going gets weird, the weird turn pro.


  7. #7
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    Thanks Chad

    No its not a video system , just colour changing panels. I'm concerned about normal led flicker and also the modulation issues when color mixing is used . I believe this is something to do with multiplex signals and PWM .

    Thanks .

    Fluff
    The light at the end of the tunnel. Its' a white laser.
    www.rocknite.co.uk

  8. #8
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    I think the PWM will be in the kHz range, while the camera's are in the Hz range so I think there will not be any problems

  9. #9
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    Quote Originally Posted by FourDee View Post
    I think the PWM will be in the kHz range, while the camera's are in the Hz range so I think there will not be any problems
    Unfortunately not always, some LED stuff, not necessarily just the cheap end either, uses an overstretched MCU to handle everything with resulting PWM rates being in the low 00s Hz.

    With video it can be a problem even with high frequencies of hitting beat frequencies and creating moire patterning.

    In reality though TV is LED mad nowadays and most systems can be made to play well with cameras, nothing beats getting a sample in before time is tight and testing it with the camera though....

    RML are a big name in TV effects lighting , unless your quoting against them, mebbe worth asking some advice

    http://www.richardmartinlighting.co.uk

    Still the nicest LED lit panel, very thin, definitely TV friendly

    http://www.lagotronics.com/lagoled-deko-panels.htm

    HTH
    Adam

  10. #10
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    Fluff. I worked with those panels. Actually still do. LED wall has a controller into which you patch my Serial port. It has all the setting to eliminate anything you don't want. Warning it will be a mind blowing experience trying to understand whats going on because it was designed by engineers for engineers. And manual normally doesn't help.
    WARNING. Always save the default settings. I didn't and I had to spend few hours making LED wall work again.

    But there is easier way. My friend who is a professional videographer. He just adjust something in his camera and everything looks fine. BTW same for lasers. But this one is easier. I just look in the camera and adjust the speed until image is stable.
    I hired an Italian guy to do my wires. Now they look like spaghetti!

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