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    AF101 shutter problem?

    Hi,

    I'm having a weird problem with my AF101.
    When recording a greenscreen scene I noticed a strange light fenomenon occuring.
    Now, this has occured before, with different light sources but I've yet to figure out what I might have missed in the camera settings. It looks alot like the shutter is to high, but it was set at 1/60 and we were recording at 25 frames per second 1080p.

    Does anyone have quick fix for the problem seen in the picture below? (The darker areas and whiter areas move downward slowly, but a clearly visible when the picture is crushed with curves.)
    The lightning from the lights (flourescent lights) are very even on the greenscreen, so I don't think that's a problem.

    /Carl

    Sequence 01.Still001.jpg

    #2
    If you are shooting at 25fps, I assume you are shooting in a 50hz country. I think your shutter needs to be set at 172.8 or something like that to avoid the strobing of the fluorescent lights.
    "If they move, kill'em!"

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      #3
      25P should be 1/50 - ie 50hz matching the power on the lights (unless you;re running 60hz lights?).

      Comment


        #4
        Thanks for your replies!

        Well, I'm in Sweden, and I do belive it's 50Hz here.
        Yes, and I tried that too! In fact, I tried most of every shutterspeed/setting but these problems still remained, although with 1/60 they were the most invisible to the naked eye (however, in post they showed up and really frustrated me). And these lines can be shown even when there's no lights around (just lightbulbs/natural sunlight). IŽll try to find a still from that scenario as well.

        I did, however, see a significant improvement when switching from Film to Video Cam in the camera settings.

        It's very probably I might have missed something in the settings. I'm still getting to grips with the camera itself, even after 5 months.

        /Carl

        Comment


          #5
          If the light seems to be pulsing its def the shutter speed setting and should be 50 or multiples of 50 shutter speed.

          Steve
          http://www.wedding-video.co.uk

          Comment


            #6
            Carl,
            I agree with what the others have said about matching your shutter speed to the frequency of the AC power going to the lights. If using dimmible LEDs, put them on full power. I've heard reports from others that some LED units can cause problems when dimmed. But I don't understand why you would have this problem with regular incandescent bulbs.... strange.
            Last edited by Ken Hull; 06-06-2012, 03:39 PM. Reason: Ooops! I had said "flo" when I meant "LED".

            Comment


              #7
              Again, thanks for your replies!

              IŽll have a look at the shutter speed again and see if I can match it up better. IŽll post the results as soon as I can!

              Comment


                #8
                You can run into troubles also, if the electrical ballasts of your lighting equipment are not good - then you may get the odd "creeping shadows" because they may produce interferences - but this is all very "old school" problems one would think. In few cases grid-frequency may shift a bit (very unusal in Europe though).

                Again, the best source of advise about that:
                http://www.davidsatz.com/aboutflicker_en.html
                http://www.davidsatz.com/flickercalculator_en.html
                writer/director/producer
                www.22ndplot.de
                http://www.vimeo.com/user1958347

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