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  1. Hello, I demonstrate old vintage ceiling fans and post videos up on Youtube.. I noticed with fans that run really fast the camera tends to start flickering color streaks and the brightness of the back ground also flickers when the fan runs at a certain speed. Here is a video to prove what I'm talking about.. at 57 seconds.. Sometimes it does it for a few seconds sometimes I does it depending if the fan stays at a certain speed to where the camera interferes.. If you pause and unpause the video a few times around 57 secs you'll see the color streaks change from purple and green..

    http://youtu.be/-kFKetkZJzc


    I tried the flicker 50 hz and 60 hz setting and the auto shutter and none of them do anything to fix the issue.. I think there for fluorescent lighting anyways which I'm using natural sunlight as the light source.. I was using a cheap Flip video before I got the cannon and it didn't have this issue.. I don't know the term for this issue, maybe someone could help..

    Thanks..
    Last edited by ada1985; 7th Jan 2013 at 18:40.
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  2. It's what happens when the accelerating rotation speed of the blades syncs and unsyncs with the frame rate speed of the camera. You need to find a speed where they "like" each other. Slowing down the shuitter speed can help but you don't say how much control you have on your camera.

    You got off easy:
    http://www.youtube.com/watch?v=LVwmtwZLG88
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  3. aBigMeanie aedipuss's Avatar
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    not sure what you are on about. i see the expected jelly roll cmos sensor problem but not much else. maybe the other cam had a different shutter speed and you failed to notice the shutter to rotation motion changes.

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  4. I'm talking about the color flicker and background strobe as smrpix said.. and only does it depending on the speed of the blades.. Is there a setting for this or a fix or something? I was using a $60 Flip Video HD camera before I bought a $300 Cannon, and there wasn't a flicker issue with the cheap Flip Camera..
    Last edited by ada1985; 7th Jan 2013 at 18:51.
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  5. Other than using a dimmer to control the fan's speed I'm not sure what to tell you. Prosumer and Pro cameras starting in the $3500 range and up give you much more control of the shutter.

    It's the same effect as when wagon wheels seem to go backwards in old westerns. (I don't know what a three-strip technicolor camera cost but I bet neither of us wants to pay it.)
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  6. $3500... Ouch
    Last edited by ada1985; 7th Jan 2013 at 19:06.
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  7. I'm not talking about the backwards effect of the blades.. I know that shutter speed and blade speed give a effect as it goes faster or slower.. I know that and all cameras do that.. I'm talking about the the background flicker and the color running when the fan reaches a certain speed.. That doesn't look normal.. as the picture posted above shows it still and you see the color is off in areas of the picture.. The background even flickers which isn't even related to the fan or blades..
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  8. Use longer exposure times. Some of the pink discolorations might come from poor deinterlacing. You should post a sample of your source, not re-encoded Youtube videos.
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  9. The pink is there in the raw file too.. but these colors are only off balance when the colors and background are flickering... Is everyone saying this is part of the strobe effect? I've never seen anykind of strobe effect on any part of a image that isn't moving..
    Last edited by ada1985; 7th Jan 2013 at 20:12.
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  10. Originally Posted by ada1985 View Post
    Is everyone saying this is part of the strobe effect?
    No. Other things to try: shoot wider, use more background lighting.
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  11. Interesting. The flourescent bulbs flicker in the background when the blade gets fast -- but not the wood.
    Edit: now I see it in the wood, also softer focus.

    I wonder if your camera is trying to adjust itself to the moving blade by adjusting the shutter speed and exposure simultaneously. The green and pink may also have something to do with the way the chip is debeyering the color -- but this is a guess. You aren't fooling with the 50/60Hz thing while the camera is rolling are you?

    Can you manually lock the shutter and exposure on the camera?
    Last edited by smrpix; 7th Jan 2013 at 20:25.
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  12. Originally Posted by smrpix View Post
    Interesting. The flourescent bulbs flicker in the background when the blade gets fast -- but not the wood. I wonder if your camera is trying to adjust itself to the moving blade by adjusting the shutter speed and exposure simultaneously. The green and pink may also have something to do with the way the chip is debeyering the color -- but this is a guess. You aren't fooling with the 50/60Hz thing while the camera is rolling are you?
    That's what I'm trying to say, there's major flickering in the back ground and color running.. Can't really tell the flickering on the wood seeing how it's barley visible, but the other white fan in the back ground which is off, you can see it flicker too.. and as you said it only does it when the blades get up to speed.. If you look at some of my recent videos it seems to do it according to blade speed and I think lighting situations effect it too.. I also dropped my camera a few weeks ago, (only about a foot onto concrete) hoping i didn't screw something up.. I didn't have the camera that long either.. I'm trying to figure out if it's something that got damaged, or maybe a setting that's causing this or it's just normal with this camera.
    Last edited by ada1985; 7th Jan 2013 at 20:44.
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  13. I can adjust the exposure manually on this camera, I think I did on one video and the video turned out perfect, Maybe I should manually do that again and see if the problem goes away..

    Shutter I'm not sure, I think there is no setting for that..


    I'm not touching the 50/60Hz thing when shooting, on that part of the video I'm not even touching the camera.
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  14. I just did another shooting today, with the Exposure in manual mode and it still made the flicker along with flashing color...
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