light phasing problem
 

I just did a shoot where I had some issues with the phasing of the lights in a couple of shots example below). Does anyone know of a technique or plugin for vegas that will lessen/remove the banding?

Password: dvinfo

Many thanks,
Henry

Re: light phasing problem
 

If you're referring to the strobing, the only fix I know of for that is to adjust your camera shutter speed, which you probably had set very low while recording this. In post, I don't know of a cure for that.

Mark

Re: light phasing problem
 

Hi Mark, many thanks for taking the time to watch the footage and reply. It's greatly appreciated. I shot the footage at 50/1. I tried every shutter speed up to and including 100/1 to remove the strobing but all were worse, so I can only assume the venue was using a mix of lights with different Hertz rates. I'm aware that people have used the CCB flicker removal plugin with good results but was hoping to avoid paying that much money. If you, or anyone else, has any ideas I'd be really grateful.

Thanks again,
Henry

Re: light phasing problem
 

This happens with a lot of modern LED setups. Often the cheaper ones when they use a mix of different coloured LED's to make a new colour i.e mixing red and blue to make a purple. Lower shutter speeds will make the strobing slower so a little harder to notice.

This has only finally gone away since moving to Canon C100's where you can dial in the exact frequency that the lights work on.

Once you've got it. I've found no way to remove it in post.

On the day, when we used to get it we would talk to the lighting guy to find a colour (usually one of the primary RGB) that didn't strobe and ask them to leave it at that. This often leads to 'Well the video guy the other week didnt have a problem'. To which we reply 'He most likely did, he just didnt do anything about it'.

Re: light phasing problem
 

This plugin will fix it...
Flicker Free Plugin : Deflicker Video Time Lapse and Slow Motion / High Frame Rate for After Effects, Final Cut Pro, Premiere, Davinci Resolve :: Digital Anarchy

Re: light phasing problem
 

Thanks very much for the info Danny. Most helpful to have suspicions confimed and good idea for a fix in future. And thank you for the suggestion Nicholas, I tried the openfx beta of the Digital Anarchy plugin. It completely fixed the issue so you just saved me $149 more on the CCB flicker removal tool :)

Re: light phasing problem
 

I can't see the video but it sounds like pulse width modulation

Pulse Width Modulation is NOT Your Friend by Art Adams

I have a venue with this and it's a nightmare. you can adjust your shutter speed to minimise but as soon as they dim the lights or brighten them the problems is back - there is no flicker on full power only when dimmed.

The only real solution is a camera with syncro scan. I have had great success with BCC flixer fixer but it's time intensive

Re: light phasing problem
 

You may also find this tutorial useful. It is not for Vegas, though:

Re: light phasing problem
 

Many thanks Paul and Adam! Both really interesting posts. I'm learning a lot today!

Henry

Re: light phasing problem
 

You’re quite welcome, Henry.

Re: light phasing problem
 

Henry, unfortunately there are lots of cheap LED lights being sold worldwide right now and causing issues for video everywhere they're used. I'm a lighting designer and purposely steer away from cheap "American DJ" type lights. If you ever have the opportunity to give lighting advice, make sure they buy LED's that specifically say "Flicker Free".

The old adage of "You get what you pay for" holds true in lighting as well. Very few videographers know much about lighting. With light being the prime ingredient of a video project, I think all videographers should learn as much as they can about it about it.

Re: light phasing problem
 

I had same issue recently, the DJs cheap lights were all over the cake, completely ruining everything. Changing shutter speed, color temps did almost nothing to help.

He kindly turned off his lights during cake cutting and all was well.

Re: light phasing problem
 

As an LD myself, most of the video complaints about lighting come from people who use clever cameras and attempt to use higher shutter speeds. Outside everyone knows the problems high shutter speeds can produce with odd strobing and flickering. Discharge lighting is inherently flickery at certain frequencies and now we have LED that has an unusual problem in the PWM is used to dim them in many designs, and the cheaper ones with less care put into the design do get very flickery - even to the naked eye - at low brightness levels. The old complaint they were too dim seems to have gone because they're now very bright, so often need throttling back. Having a camera on the go with higher shutter speeds dialled in is not going to get better. I'm also seeing lots of the blue blur posts, where lighting people love the new deep blue and pile it on, but some cameras, often Sonys, just can't handle it. Maybe we should look to the camera manufacturers to sort this?

I've not noticed the problem as bad with 25fps settings - and that's what I use when I'm also lighting. What I don't understand is why wasn't the problem spotted in the viewfinder?

Re: light phasing problem
 

Henry,

Set PHASERS to STUN!

Re: light phasing problem
 

beam me up scotty, there's no intelligent life down here ;-)