View Full Version : filming fluo lights


Tom Van den Berghe
June 24th, 2014, 12:47 PM
I noticed everytime I film something with fluo lights the image is much too saturated. It blows that fluo color too much.

I always film without a preset. Didn't had time to test presets.

I attached 2 samples. How I can avoid this?

My previous cam sony HXR-NX5 had an ioption in the menu "reduce flicker" for that. I can't find that option into the nex-ea50.

Chris Harding
June 24th, 2014, 07:32 PM
Hi Tom

Were you in full auto or totally manual ? That whole image looks like you have 30db gain and the white balance has gone out the window ... Sure it was fluro? That to me looks like the horrible cast you get from blue LED lighting and it's a killer too ...the cameras white balance cannot handle it and some theatres have started using LED lighting because it's so energy efficient. In very low light not only does the autofocus not work well at all, but the white balance also has issues.

Those are stills so we cannot see any flicker but if you are filming in progressive (like 25P or 50P) then yes, you will get flicker with a shutter at 1/50th in Europe cos the mains frequency is 50Hz ... the only solution for progressive to stop flicker is to use a shutter of 1/100 which drops your light a huge amount so you would need a much faster lens!! I do indoor stuff with lighting all in 50i and interlaced footage can handle flicker much better and you then drop it into a 25P timeline after de-interlacing and you have no flicker.

Chris

Peter Rush
June 25th, 2014, 05:22 AM
Looks like the dreaded LED to me - a lot of DJs now use them but worse is when a band a wedding reception use them - renders a lot of the footage of the band themselves useless IMO - impossible to white balance :(

Chris Harding
June 25th, 2014, 05:44 AM
The only way I get over it at weddings is keep a really tight shot and then zap the subject with decent light and you can get away with it. In this case where the camera is a long way from the subjects you are basically sunk !! It will also play absolute havoc with autofocus. In the wide shot scenario there is precious little you can do with lighting like that and a bit of flicker, to me would be better to contend with than that terrible blue cast ...it would make a great set however for a nightime horror movie but that's about all!!

Chris

Peter Rush
June 25th, 2014, 05:58 AM
With bands Chris I get very close but still my on camera light barely makes an inroad into the powerful and horrible wash of blues and magentas of some of these lights - truly horrible!

Paul R Johnson
June 25th, 2014, 06:08 AM
Guys - you are going to have to get used to this. Blue has always been a desired colour - pop/rock concert Lighting Designers have used it for years - Lee 181 Congo was the solution - BUT - it passed less than 1% of the light going through it, so getting decent levels was impossible without big budgets, and lots of kit.

Now with LED, they have for the first time a bright saturated blue - exactly what they want. The fact that some video cameras cannot handle it, is not their fault. If the video is more important than the effect to the audience, then the lighting can be adjusted in the planning phase. All my work is in this area, and for years, the BBC turning up at a theatrical event meant blasting the hell out of the levels, removing shadows, and giving people suntan! Then cameras became more sensitive and normality returned, but now you have colours to contend with.

It does seem that some cameras have poor handling of colour when it comes to auto exposure, deciding the illumination is wrong, and adjusting the exposure badly.

We have lighting, sound and video people, and they all get compromised by each other. In the end somebody suffers. Video often was considered the primary medium, so sound couldn't get their boom in, and the lighting was 100% for the picture. That is NOT the case any more. Tungsten lighting isn't being dumped for economy reasons, but for performance reasons - RGBA colour mixing means the designer can have whatever they want, and at the moment, they want blue.

It is not going away, and to be honest, I rather like the blue look on those musicians - sure the camera needs looking at. Focus and exposure are important things to get right. Some cameras do handle the blue ok. My HD JVCs are not bad at all on auto exposure.

I have a booking this weekend, and one of the early questions I asked was about the lighting. The organiser still hasn't got back to me, so I'm going to have to take what I find.

As I'm also a Lighting Designer, I won't be asking for changes on the day. If they ask, I'll suggest a few things to help me. If, they've spent ages setting states for the show, even though they could, I'll not be asking them to change. A bit like asking the director to brighten up a scene for technical reasons, when he wants it dark.

LED lighting for shows is getting more colourful - and it's good! If you want white skin, then find the extra budget for quite a few facelights!

Peter Rush
June 26th, 2014, 08:25 AM
I filmed a wedding a few weeks ago and I'm now looking at the evening footage and the room was awash with these lights and my footage is all pretty much under exposed - easily fixed but is it possible these lights fool my zebras?

Paul R Johnson
June 26th, 2014, 09:21 AM
I suspect they do. The trouble is that the output spectrum is just huge spikes of colour - so there is a massive burst of blue at a very tight range of wavelengths, and the rest is nothing. I'd assume that the measurement of light level from a typical camera is designed to look at a range of wavelengths, so the exposure indicates it's not what it really is. I think some brands respond quite differently. Panasonic and JVC (what are available to me) are quite happy, but I did try my old Betacam, which was never that comfy with red, and red LED light sparkles amazingly, while the blue kind of glows.

I've just had some info come through about my weekend dance show, and one scene has a note for the lighting people saying - Wicked. As much green light as is possible, followspot for the principal. I've not seen what saturated green looks like, as people normally hate green, as it does horrid things to dark skin. It will be a new one for me.

Tom Van den Berghe
June 26th, 2014, 01:35 PM
Hi Tom

Were you in full auto or totally manual ? That whole image looks like you have 30db gain and the white balance has gone out the window ... Sure it was fluro? That to me looks like the horrible cast you get from blue LED lighting and it's a killer too ...the cameras white balance cannot handle it and some theatres have started using LED lighting because it's so energy efficient. In very low light not only does the autofocus not work well at all, but the white balance also has issues.

Those are stills so we cannot see any flicker but if you are filming in progressive (like 25P or 50P) then yes, you will get flicker with a shutter at 1/50th in Europe cos the mains frequency is 50Hz ... the only solution for progressive to stop flicker is to use a shutter of 1/100 which drops your light a huge amount so you would need a much faster lens!! I do indoor stuff with lighting all in 50i and interlaced footage can handle flicker much better and you then drop it into a 25P timeline after de-interlacing and you have no flicker.

Chris

Chris, I was in full auto and gain limited @ 24db. Was filmed in 50i this time. final product will be dvd.
not fluo but blue led lightning I suppose. So next time film in manual and set white balance at indoor?

Thanks for all the replies already!

Noa Put
June 26th, 2014, 02:38 PM
but if you are filming in progressive (like 25P or 50P) then yes, you will get flicker with a shutter at 1/50th in Europe cos the mains frequency is 50Hz ... the only solution for progressive to stop flicker is to use a shutter of 1/100 which drops your light a huge amount so you would need a much faster lens!!

You will not get flicker shooting 50p and by choosing a shutter of 1/50, I shoot like that a lot and don't have any issue, unless they use cheap led's, but then 1/100 shutter doesn't solve the problem either but often I have to choose 1/30, 1/40 or 1/60 to get rid of it.

Tom, was that blue color the only color used? you could try to use a very flat preset and dial down the saturation as much as possible as you can still add that a bit in post. You could also dial down saturation in post on the recording you have now, that will bring back detail as well.

Tom Van den Berghe
June 27th, 2014, 02:18 PM
yes Noa, was also red color. I think it was because of full auto and the white balance that was not correct.
I will correct it in post like you said. thanks.

Tom Van den Berghe
July 6th, 2014, 11:53 AM
Last weekend I filmed at a birthday party from a friend. Again the blue lights from the discobar were not good.
This time I filmed with a prime lens, manual focus, gain was 12db or lower and WB indoor preset.

Even if I lowered the gain it maked no difference with the blue lights.

Also focus manually with peaking was almost impossible with those lights. I could not see on the lcd screen what was in focus or not. I use yellow color for peaking.

Here is a part of that footage.

https://www.youtube.com/watch?v=y7juFA8PizY&feature=youtu.be

Noa Put
July 6th, 2014, 12:39 PM
Yeah, that kind of blue and the other kind of horrible red are my camera's best friends. As far as I know there is not much you can do about it unless you would add a very strong videolight onto your camera to flood the dancefloor with white light but then the guests would not be your best friends anymore :)

Last year I canceled a order I made for a videolight on a high light stand that I could control with a remote to place next to the dancefloor, the problem is with these DJ lights is that you need a very powerful light to have enough white fill light, it would be easier to just cut the power cable to his lights. :)
I did not buy that light as I realized it's yet another tool to drag along that day and in most cases it won't work as it won't be powerful enough and for other conditions where they kill most of the light my GH3 at 6400 iso with a f2.0 lens can show me more then what I see with my own eyes.

I wonder if you could use a preset that doesn't wash out all details like that blue or red light does, have you tried shooting with a very flat preset? Maybe that would work better to add saturation afterwards in post?

Chris Harding
July 6th, 2014, 05:50 PM
Hi Tom

The only way you can contend with the DJ lights is to firstly try to film with your back to the lighting (it doesn't help much but at least you are not shooting straight into the source) Unless the lighting is really high you can block the light just a little with your head (every little bit helps)

Secondly and the best solution so far I found is keep shots really tight (just a couple dancing at a time) and zap them with an on camera light. I used a 6 PowerLED light last time and as long as you stay tight it at least kills that horrible distorted blue haze you get on their faces which makes them actually look fuzzy and out of focus ... You can see in your sample that focus is perfect until the light turns blue then it looks terrible until the colour changes. I did a solo guitarist at a wedding a few months ago and areas lit by my video light were perfect but outside that the blue light killed everything!

Of course the real answer comes from Noa .. cut the lighting cable!!!

Chris

Steve Bobilin
July 6th, 2014, 07:35 PM
Since these lights are par for the course nowadays,(no pun intended), perhaps one of you clever people could figure out a special Picture Profile recipe just for LED dance related parties and receptions. I should imagine It would involve a great deal of experimentation at a real party situation with a good monitor.

Tom Van den Berghe
July 7th, 2014, 01:53 PM
Yeah, that kind of blue and the other kind of horrible red are my camera's best friends. As far as I know there is not much you can do about it unless you would add a very strong videolight onto your camera to flood the dancefloor with white light but then the guests would not be your best friends anymore :)

Last year I canceled a order I made for a videolight on a high light stand that I could control with a remote to place next to the dancefloor, the problem is with these DJ lights is that you need a very powerful light to have enough white fill light, it would be easier to just cut the power cable to his lights. :)
I did not buy that light as I realized it's yet another tool to drag along that day and in most cases it won't work as it won't be powerful enough and for other conditions where they kill most of the light my GH3 at 6400 iso with a f2.0 lens can show me more then what I see with my own eyes.

I wonder if you could use a preset that doesn't wash out all details like that blue or red light does, have you tried shooting with a very flat preset? Maybe that would work better to add saturation afterwards in post?

Noa, I always film without a preset (no preset selected) Still haven't tried filming with presets. So I suppose this a flat preset.

Paul R Johnson
July 7th, 2014, 03:16 PM
In the disco clip, there is another feature that makes the result worse. Traditional tungsten lamps ramp up and down. A PAR64 takes nearly half a second to go out, for example. LEDs goin on and off instantly, and that makes it look even worse, as in the clip.

However, I bet to those there, it looked so much better.