Wavy scrolling in video

[karri]

Hi Everyone,

You know when you video a TV and it has a wavy scrolling effect in the video? I took some video and it has a similar effect and I'd like to get rid of it, if possible. This is the second time it happened and the only common link I can come up with is that I had used my light with the warming filter on it. Would that cause this effect?

Filming with an HV30 at TV 60i and all the footage is good, except for the one clip I used the light with, because we were in a dark room.

Thanks for any help!

karri

[Steve Grisetti]

Are you talking about what's called the moire effect, karri? This is what commonly happens when you shoot video or take pictures of someone wearing a pin-striped suit or someone standing in front of venetian blinds.
http://guides.lib.umich.edu/content.php ... sid=337530

If it's not that, can you post a sample of what you're describing?

[karri]

Thanks Steve, here is a sample. It is most noticeable on the right side (where it is lightest) but goes across the whole screen.
http://www.youtube.com/watch?v=7rOvQSkCzS0
Thanks for help!

[Steve Grisetti]

I'm not sure, karri. It could be a moire effect, caused by the light coming through the black curtain. Or it could be your camcorder just adding noise in a low-light situation.

[Bob]

It could possibly be related to the lighting. Some types of ac powered lighting pulse light and dark as the ac power goes through it's cycle and that can be picked up with a fast enough shutter and can appear as darker bands on the image. If the shutter speed of the camera is slightly different from the ac frequency, you can get a rolling band effect similar to what is showing in your sample. What type of a light are you using? Is it an incandescent light, a flourescent light, or something else? Does it run from a battery or do you plug it in to an outlet? How bright is it compared to the room lighting? Is the room lighting flourescent?

[karri]

Thanks Bob, This is the light http://www.bhphotovideo.com/bnh/controller/home?sku=588827&Q=&O=&is=REG&A=details

It is a dimmable LED light that runs on battery. I can't remember for sure, but I think the lights in the room were off. It was a very small room and dark because it was being used by a puppeteer of sorts, if you could tell from the clip. He was in a dark room behind a black curtain. The last time this effect happened I was in a ballroom and the lights were on, but I'm not sure what kind of lighting. Both times I had the dimmer set to about 20-40%.

Thanks for your help!