Removing Flicker From Florescent Lights? at DVinfo.net

Jeff Wallace · July 1st, 2011, 12:24 PM

Hi All,

I just received some interview footage shot in 30p on a Sony EX3 and the image is flickering badly -- probably from the florescent lights in the room. It was shot in Singapore so I have no idea what the conditions were over there.

Is there a way to reduce or remove this kind of flicker? A deinterlace filter doesn't work since the footage is progressive.

Any input would be appreciated!

Oyana Beasley · July 1st, 2011, 12:38 PM

I havent used it but I read on a board that you can use Lock & Load X - The Worlds Fastest Video Stabilizer for Final Cut Pro

Director Of Post Production
KAR STUDIOS LLC
info@karstudios.com

Paul R Johnson · July 1st, 2011, 01:25 PM

Singapore uses 25fps PAL - with 50Hz mains - so the real snag here is that fixing it is going to be really tough because the flu tubes were dark during some of the time your 30fps shutter was open. I've never found a solution to this one - but hopefully somebody may know a technique that could reduce it?

Jeff Wallace · July 1st, 2011, 01:37 PM

Hi Paul,

The clip info says it was shot 29.97. Is there a way to verify if the footage is PAL or NTSC?

>>Singapore uses 25fps PAL - with 50Hz mains - so the real snag here is that fixing it is going to be really tough because the flu tubes were dark during some of the time your 30fps shutter was open. I've never found a solution to this one - but hopefully somebody may know a technique that could reduce it?<<

Arnie Schlissel · July 2nd, 2011, 12:06 PM

The Foundry has a deflicker filter that works well for this in the Furnace Core series: FURNACECORE | Features | The Foundry

Jeff Wallace · July 2nd, 2011, 07:16 PM

Thanks Arnie! I will check it out.

It looks like the footage was shot at shutter speed 60 in NTSC, so that must be the problem.

Tim Dashwood · July 3rd, 2011, 09:59 AM

Quote:

Originally Posted by Jeff Wallace

The clip info says it was shot 29.97. Is there a way to verify if the footage is PAL or NTSC?

It is HD in 29.97fps. That isn't as relevant as the shutter speed used. In the future you should use a shutter speed that matches the power mains of the country you are shooting in if there is a non-tungsten light source.
For most of the world this means you should tune in 1/50th shutter (regardless of frame rate). In North America you can use 1/60th shutter or 1/48th (for 24p.)

I have seen lots of plugins that supposedly smooth out flicker but I've never seen one actually work very well.

Years ago I was given footage that was shot high speed (overcranked) with HMI sources with an analog ballast (sine wave.) All the footage was flickering so in the final telecine select-scene transfer we literally adjusted the level on each frame until we smoothed it out to make it passable. It was a 30 second commercial but it still took a couple of days!

Paul R Johnson · July 3rd, 2011, 02:48 PM

The worst thing with flu tubes is they flicker even when the camera is at the same rate (or multiple) of the mains frequency. High camera shutter speeds are much worse when the frame rates don't match - and if the result is the shutter was open when the flu was out - the flicker removers have very little to work with.

Jeff Wallace · July 6th, 2011, 02:42 PM

The De-Flicker filter in FurnaceCore actually works to correct this problem, but it's extremely buggy and renders insanely slow. For a 20 second clip, it can take 3 hours to render... ouch. And then sometimes it crashes half-way through a render.

Does anyone know if there's a similar app that's more stable? I've tried a bunch of other plugins but nothing works so far except FurnaceCore.

Steve Oakley · July 6th, 2011, 10:21 PM

try the after effects color stabilizer

Jeff Wallace · July 6th, 2011, 11:34 PM

Hi Steve,

I tried this, but can't make heads or tails out of it. Are there any tutorials anywhere? It only seems to make the flickering worse. I don't understand how to set the Black and White points.

FurnaceCore DeFlicker is great step in the right direction. It's pretty amazing that it completely eliminates the flicker, but it's a flimsy plug-in and The Foundry have a lot more work to do on this before it's stable. Currently it's behaving like an early Beta release. Perhaps it does fine with SD footage, but really chokes on HD 1080p.

Steve Oakley · July 7th, 2011, 12:06 AM

the black and white points are set by setting the X/Y points in the filters for each level. use AE's help. it may or may not do the job. it does work for fixing some types of image flicker like in stop animation. your flicker may be more then it can deal with. so look at the AE help first online.

as for the foundry plug, I guess it depends how much material you need to fix to decide if its worth getting.

July 1st, 2011, 12:24 PM	#1
Jeff Wallace Regular Crew Join Date: Jan 2010 Location: San Mateo, CA Posts: 79	Removing Flicker From Florescent Lights? Hi All, I just received some interview footage shot in 30p on a Sony EX3 and the image is flickering badly -- probably from the florescent lights in the room. It was shot in Singapore so I have no idea what the conditions were over there. Is there a way to reduce or remove this kind of flicker? A deinterlace filter doesn't work since the footage is progressive. Any input would be appreciated!

July 1st, 2011, 12:38 PM	#2
Oyana Beasley Tourist Join Date: Jun 2011 Location: Camarillo, CA Posts: 2	Re: Removing Flicker From Florescent Lights? I havent used it but I read on a board that you can use Lock & Load X - The Worlds Fastest Video Stabilizer for Final Cut Pro Director Of Post Production KAR STUDIOS LLC info@karstudios.com

July 1st, 2011, 01:25 PM	#3
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,016	Re: Removing Flicker From Florescent Lights? Singapore uses 25fps PAL - with 50Hz mains - so the real snag here is that fixing it is going to be really tough because the flu tubes were dark during some of the time your 30fps shutter was open. I've never found a solution to this one - but hopefully somebody may know a technique that could reduce it?

July 1st, 2011, 01:37 PM	#4
Jeff Wallace Regular Crew Join Date: Jan 2010 Location: San Mateo, CA Posts: 79	Re: Removing Flicker From Florescent Lights? Hi Paul, The clip info says it was shot 29.97. Is there a way to verify if the footage is PAL or NTSC? >>Singapore uses 25fps PAL - with 50Hz mains - so the real snag here is that fixing it is going to be really tough because the flu tubes were dark during some of the time your 30fps shutter was open. I've never found a solution to this one - but hopefully somebody may know a technique that could reduce it?<<

July 2nd, 2011, 12:06 PM	#5
Arnie Schlissel Major Player Join Date: Jul 2006 Location: New York NY Posts: 322	Re: Removing Flicker From Florescent Lights? The Foundry has a deflicker filter that works well for this in the Furnace Core series: FURNACECORE \| Features \| The Foundry __________________ Post production is not an afterthought! www.arniepix.com

July 2nd, 2011, 07:16 PM	#6
Jeff Wallace Regular Crew Join Date: Jan 2010 Location: San Mateo, CA Posts: 79	Re: Removing Flicker From Florescent Lights? Thanks Arnie! I will check it out. It looks like the footage was shot at shutter speed 60 in NTSC, so that must be the problem.

July 3rd, 2011, 02:48 PM	#8
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,016	Re: Removing Flicker From Florescent Lights? The worst thing with flu tubes is they flicker even when the camera is at the same rate (or multiple) of the mains frequency. High camera shutter speeds are much worse when the frame rates don't match - and if the result is the shutter was open when the flu was out - the flicker removers have very little to work with.

July 6th, 2011, 02:42 PM	#9
Jeff Wallace Regular Crew Join Date: Jan 2010 Location: San Mateo, CA Posts: 79	Re: Removing Flicker From Florescent Lights? The De-Flicker filter in FurnaceCore actually works to correct this problem, but it's extremely buggy and renders insanely slow. For a 20 second clip, it can take 3 hours to render... ouch. And then sometimes it crashes half-way through a render. Does anyone know if there's a similar app that's more stable? I've tried a bunch of other plugins but nothing works so far except FurnaceCore.

July 6th, 2011, 10:21 PM	#10
Steve Oakley Trustee Join Date: Apr 2006 Location: United States Posts: 1,158	Re: Removing Flicker From Florescent Lights? try the after effects color stabilizer __________________ Steve Oakley DP • Audio Mixer • Editor • Colorist http://stevenoakley.com

July 6th, 2011, 11:34 PM	#11
Jeff Wallace Regular Crew Join Date: Jan 2010 Location: San Mateo, CA Posts: 79	Re: Removing Flicker From Florescent Lights? Hi Steve, I tried this, but can't make heads or tails out of it. Are there any tutorials anywhere? It only seems to make the flickering worse. I don't understand how to set the Black and White points. FurnaceCore DeFlicker is great step in the right direction. It's pretty amazing that it completely eliminates the flicker, but it's a flimsy plug-in and The Foundry have a lot more work to do on this before it's stable. Currently it's behaving like an early Beta release. Perhaps it does fine with SD footage, but really chokes on HD 1080p.

July 7th, 2011, 12:06 AM	#12
Steve Oakley Trustee Join Date: Apr 2006 Location: United States Posts: 1,158	Re: Removing Flicker From Florescent Lights? the black and white points are set by setting the X/Y points in the filters for each level. use AE's help. it may or may not do the job. it does work for fixing some types of image flicker like in stop animation. your flicker may be more then it can deal with. so look at the AE help first online. as for the foundry plug, I guess it depends how much material you need to fix to decide if its worth getting. __________________ Steve Oakley DP • Audio Mixer • Editor • Colorist http://stevenoakley.com