Wavey footage on GH2?

[Foggy]

I have shot quite a lot with my GH2 now with no problems until today.

I shot some footage in a hallway,the shot shows an actor looking in the mirror and is shot over his shoulder so you can see it is him in the mirror.

The shoot was good and the footage looked really nice but now I have imported it onto my laptop it has a strange wavey effect on it.The effect isn't over all of the shot,just a portion around the mirror seems to have a wavey flickering over it.

I am wondering if its maybe the lighting?Or how Ive imported it?Or even the frame rate I shot at?

Any advice is hugely welcome.

Cheers.

 

[Lucky Hardwood]

How about giving us some specifics. What were your camera settings? What NLE are you using? How did you import the footage? What compression? Have you checked the footage on a different computer? What display are you using?

 

[Foggy]

Sorry I shouldn't have written that last post in a hurry. Camera was at 24FPS ISO160 F1.4,I am watching the footage back in quicktime having imported straight from MPEG Streamclip where it was converted from MTS to Apple proxy 422(LT).I have only looked at it on my 2011 Macbook Pro screen.

 

[Foggy]

Ok having done a few experiments it seems the problem is fluro lighting,apparently it works at a low frequency and so the camera picks up the flickering as it effectively turns on and off.I do a lot of filming at University and most of the rooms have fluro lighting,I went from a room with fluro lighting and filmed near the light and had the flickering,then kept all the same settings on the camera and went into a room with halogens and the flickering was gone.

How do I get around this?

 

[A.D.]

The flicker can be avoided by either using high frequency digital ballasts (not an option for you really), changing your shutter so it doesn't capture each on/off cycle (pain in the arse as it often limits creative freedom, though even a small shutter shift can eliminate it), or simply avoid rooms with oldskool flouro lights (likely your only real option).

 

[stef]

Ok having done a few experiments it seems the problem is fluro lighting,apparently it works at a low frequency and so the camera picks up the flickering as it effectively turns on and off.I do a lot of filming at University and most of the rooms have fluro lighting,I went from a room with fluro lighting and filmed near the light and had the flickering,then kept all the same settings on the camera and went into a room with halogens and the flickering was gone.

How do I get around this?

I was going to guess old fluorescents. Many use high frequencies these days, but the old ones flicker at 60 Hz (or 120?), so anything not in sync with the powerline will see changes in amount of light.

You can try shooting at 30fps which might lessen the effect, but it will still happen over time. You can also add additional lights, like a fluro gelled halogen. Or use normal halogens and turn off the fluoros. If there's not a ton of motion, you can probably experiment with the shutter speed, too, although I'm pretty sure the fps is what counts.