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Flicker from over head fluorescent lights?


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#1 Richard Lacey

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Posted 30 April 2010 - 07:27 PM

I'm shooting a film next week that has a scene in a hospital ward.

I was thinking of using the fluorescent ceiling lights that are already there to light the background and lighting the actors with a kino flo.
We're shooting for black and white so I really want the actors to pop out against the background.

Will there be any issue with flicker from the fluorescent lights?

I'm based in Ireland and we'll be shooting at 25 fps.

Edited by Richard Lacey, 30 April 2010 - 07:28 PM.

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#2 David Mullen ASC

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Posted 30 April 2010 - 07:42 PM

I'm shooting a film next week that has a scene in a hospital ward.

I was thinking of using the fluorescent ceiling lights that are already there to light the background and lighting the actors with a kino flo.
We're shooting for black and white so I really want the actors to pop out against the background.

Will there be any issue with flicker from the fluorescent lights?

I'm based in Ireland and we'll be shooting at 25 fps.


If you are shooting with a crystal sync motor at 25 fps under 50 Hz AC lights, you should be fine except for the occasional light with a bad ballast in it.
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#3 John Sprung

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Posted 30 April 2010 - 08:15 PM

It also depends if they still have magnetic ballasts. Over here, they're a thing of the past. The electronic ballast flourescents are high enough frequency not to cause any problem at any reasonable frame rate and shutter angle -- like CFL's. We had a shoot in Thailand recently, and were worried about old magnetic ballasts. It turned out that they're even gone over there.

Of course you may find a tube going bad here and there. But those you can see just by eye, and pull them out or replace them.




-- J.S.
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#4 Richard Lacey

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Posted 30 April 2010 - 08:41 PM

If you are shooting with a crystal sync motor at 25 fps under 50 Hz AC lights, you should be fine except for the occasional light with a bad ballast in it.


Thanks for the replies.

We're shooting with an Aaton LTR.
I wasn't previously familiar with crystal sync motors, but given the age and condition of my college's camera I'm guessing it won't have one.

Edited by Richard Lacey, 30 April 2010 - 08:42 PM.

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#5 John Sprung

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Posted 30 April 2010 - 09:29 PM

The LTR's are new enough that most if not all are probably crystal. Do you do sync sound without a hard wire from the camera to the recorder? If so, it has to be crystal. If the ballasts are electronic, it wouldn't matter either way.




-- J.S.
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#6 Brian Drysdale

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Posted 01 May 2010 - 03:37 AM

Thanks for the replies.

We're shooting with an Aaton LTR.
I wasn't previously familiar with crystal sync motors, but given the age and condition of my college's camera I'm guessing it won't have one.


The Aaton LTRs have crystal sync. I'd be more worried about the green in the fluorescents than the flicker if you're shooting at 25 f.p.s with a crystal motor.
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#7 John Sprung

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Posted 02 May 2010 - 02:51 AM

Actually he's lucky on that one -- shooting B&W, so the green won't be an issue.



-- J.S.
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#8 julie kain

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Posted 05 May 2010 - 01:49 AM

Hi,

There are many types in fluorescent lights like Compact Fluorescent Bulb, Fluorescent Deluxe Floodlight, Fluorescent Portable Worklight, Fluorescent Worklight, 65 Watt Fluorescent Twin head Worklight and more. Try any of these if you are interested.
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#9 Richard Lacey

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Posted 06 May 2010 - 06:26 AM

I decided not to risk using the overhead fluorescents.
Instead I lit it with a 4 bank kino, an Arri 1K and 3 150w Dedolights.

It looked pretty good on the day.
Here's hoping the rushes look good!
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#10 Brian Drysdale

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Posted 06 May 2010 - 11:25 AM

Actually he's lucky on that one -- shooting B&W, so the green won't be an issue.



-- J.S.


Speed read past that bit.
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