Not sure what people call it.. maybe a pretty basic question.

Y

Yaz

Active member
Hi

It may be a very simple question for you guys, but I need a help here.
When I shoot HD video on DSLR, in my room at night, I get the black bars coming from below to up constantly. Is that because the room is in low light condition?
I don't know what people call it. Please tell me its name too! and how to avoid it if one can.
 
sounds like Flickering due to your shutter speed and the type of light in your room. Do you have fluorescent bulbs in there? Its a frequency cycle thing.Try changing the shutter to 1/60 (is it 1/60 in North America?) Anyway just try changing to 50 or 60 and see what happens. Dont worry nothing is wrong with the camera, if that indeed is the problem
 
Hi thnx for replying. No, i know flickering there. it's not that. mmm I don't know how to explain... Mmm...
It's like some video issue, like when you watch B&W surveillance monitor, you constantly see see black horizontal bar coming up from below and disappearing and appearing again.
Any idea?
 
rolling bars are ussualy a sync issue, so I think jambredz is right and heading you in the right direction. is there a tv or computer monitor providing the light in room? but its deff a sync issue.
 
Rolling bars? sounds about right. I have a laptop providing the light in the room, but mainly from the lamp on the ceiling. Laptop is not the sole source of the light though. No tv in the room. How do I solve this sync issue? and what exactly is a sync issue?
 
a light flickering at 50Hz and being shot at 30fps with 1/60s shutter will create a black bar that moves up through the screen

usually they're not going completely on and off in each cycle, so the bar is not black, just different shade of color (green or magenta) or just somewhat darker than the rest of the image
 
Sync issue is basically simply put that your shutter on the camera (which happens so fast your eye doesn't know its happening) is slightly off from the flashing of the lights (which also happens too fast so your eye doesn't see it , but its there), just like NormanBates explained. the way to fix it is to see what frequency your power is running at and matching shutter speed to a setting that is compatible. this happens alot when you take cameras using NTSC for American Market to Europe where they use 50hz for their power grid.
 
Ohhh, now I understand. Thanks you guys for answering my question. I'll try and fix that now.
 
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