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Slow motion with Flourescent lights and a Rolling shutter?
  • So how you all deal with shooting at faster shutter speeds in fluorescent lighting with a rolling shutter camera. I shoot a lot of slow motion indoors and so I want to shoot at higher shutter speeds. However, I get a sort of strobing affect if I go faster than 1/120th of a second.

    Will this make 120 FPS useless for these types of shots in florescent lighting?

    Here is an example of what the indoor slow motion looks like with 1/120th of a second shutter speed. I tried it with 1/250th and it puts a black bar through the video that I presume is from the rolling shutter.

    This was shot with the 25mm F1.4 and 720p @ 60 FPS with 1/120th shutter speed. It is simple slowed down video without any use of an interpolating program like Twixtor.

  • 4 Replies sorted by
  • There is "flickerfree" fluorecent like Kino Flo's but they also tend to give problems at extreme slomo. At least older models are running at 400 hz afaik.I would stay with HMI's, when switched to flickerfree they usually really are.

  • Are you in a country with 60 Hz electricity? This means 60 cycles per second, so sixty FPS is the max you can shoot if your source gives 1 light pulse per second (I believe fluorescents do). Old school magnetic ballast HMIs were 2 pulses per cycle and you could shoot 120 FPS (crystal speed only). The explanation starts halfway down the page here: http://forums.dpreview.com/forums/readflat.asp?forum=1019&message=36228130&changemode=1

  • The black bar pronounced at 1/250th is due to a lack of exposure (you are seeing what's between the pulses), it's not the rolling shutter.

  • @CFreak

    So why is it a black bar and not the entire image being black from lack of exposure? Isn't that because of the rolling shutter?

    I guess it really doesn't matter. Either way it is not going to produce good results with fast shutter speeds. I was just trying to understand exactly what was going on.

    Our climbing gym is expanding with a whole new facility. Do you guys have any recommendations on lighting that they could use that wouldn't break the bank but would fix this issue?