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Lighting tungstens and flicker at 200fps


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#1 Ale Capo

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Posted 11 April 2018 - 06:49 AM

Hi guys,

 

I did some research regarding flicker and slow but I still have a doubt and as I'm not able to test it I'd like to ask.

 

Shooting with Panaura 5 tungsten and a couple of fresnels ( 650k and a redhead 800k). most probably the fresnels will be bounced to poly and then through diffusion frame.

  

 

I have some shots at 200fps, in a 50hz country.

 

If i set the shutter speed at 1/400, apart for the fact the I'mgoing to loose 3 stops, will the panaura 5 and fresnels flicker?

 

Thank you.


Edited by Ale Capo, 11 April 2018 - 06:50 AM.

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#2 David McLeavy

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Posted 14 April 2018 - 01:43 PM

Yes it will flicker at that shutter speed and frame rate because the light dims slightly every cycle. You need at least a 2K tungsten to be bright enough that the slight dimming doesn’t read on camera. The fastest frame rate I’ve managed to shoot without any flicker with smaller lights is 120fps with an appropriate shutter speed.
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#3 Stuart Brereton

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Posted 14 April 2018 - 03:42 PM

You need at least a 2K tungsten to be bright enough that the slight dimming doesn’t read on camera. 

It's not how bright it is, it's whether the filament is sufficiently large that it doesn't noticeably dim during the AC power cycle.


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#4 Guy Holt

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Posted 14 April 2018 - 08:23 PM

...  most probably the fresnels will be bounced to poly and then through diffusion frame.

 

If you are bouncing or shooting your lights through diffusion, then you can eliminate flicker with small tungsten lights by shooting multiple lights into your bounce card  or diffusion frame.  The trick is to make sure the lights are on different legs of your electrical service.  If you are shooting in a house, where your electrical service will be single phase, then you would shoot two lights into your bounce board.  If each light is on a different leg of the electrical service, then one light will be coming up in intensity as the other light is diminishing in intensity.  The net is effect is continuous light output and no flicker. If you are shooting in an industrial setting, where your electrical service will be three phase, then you would shoot three lights into your bounce board.

 

Guy Holt, Gaffer

ScreenLight & Grip

Lighting Rentals & Sales in Boston


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#5 David McLeavy

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Posted 14 April 2018 - 11:49 PM

It's not how bright it is, it's whether the filament is sufficiently large that it doesn't noticeably dim during the AC power cycle.


Ah. Good detail to know. Thanks!
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