Jump to content


Photo

Avoiding flourescent flicker all together


  • Please log in to reply
11 replies to this topic

#1 Brandon Whiteside

Brandon Whiteside
  • Basic Members
  • PipPip
  • 62 posts
  • Cinematographer
  • Los Angeles

Posted 06 April 2009 - 10:02 PM

I started by doing a search on the topic "Flourescent flicker" and came across nothing useful. This weekend i am shooting 24p with an xl2 in a classroom, using the built in flourescents. What are the chances we experience problems?


Thanks so much!
  • 0

#2 JD Hartman

JD Hartman
  • Basic Members
  • PipPipPipPip
  • 1690 posts
  • Gaffer
  • Edison, N.J. U.S.A.

Posted 07 April 2009 - 11:47 AM

Here: http://www.cinematog...h...&hl=flicker If the fixtures have electronic ballasts, you'll probably be fine. Shoot some test footage and see what results.
You profile indicates "Student". What did your instructors advise?
  • 0

#3 Steve McBride

Steve McBride
  • Basic Members
  • PipPipPip
  • 239 posts
  • 1st Assistant Camera
  • New York, NY

Posted 07 April 2009 - 08:58 PM

Make sure your shutter speed stays at 1/60 of a second. The fluros run at 60hz which means 60 cycles a second, so when you're frame rate is 1/60 of a second you are getting 1 full cycle in the lights every 1/60th of a second which makes for 60 full cycles in a second. That basically means that the lights will look fine.

I may be completely off, or just slightly off here. Wait for someone else to confirm or deny what I have said before you trust it :) .

I also just realized that that really didn't make any sense, so hopefully someone can come through and help me out also. I'll look into it again because I know I read this not too long ago and if I find it I'll reply back.

Edited by Steve McBride, 07 April 2009 - 09:00 PM.

  • 0

#4 Brandon Whiteside

Brandon Whiteside
  • Basic Members
  • PipPip
  • 62 posts
  • Cinematographer
  • Los Angeles

Posted 08 April 2009 - 12:07 PM

I will be shooting 24p at 1/48th. What about that?
  • 0

#5 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7118 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 08 April 2009 - 12:18 PM

You should be fine 24 @1/48s. It's a safe speed.
  • 0

#6 Brandon Whiteside

Brandon Whiteside
  • Basic Members
  • PipPip
  • 62 posts
  • Cinematographer
  • Los Angeles

Posted 08 April 2009 - 01:00 PM

Yay!
  • 0

#7 Steve McBride

Steve McBride
  • Basic Members
  • PipPipPip
  • 239 posts
  • 1st Assistant Camera
  • New York, NY

Posted 08 April 2009 - 05:56 PM

Guess I was probably wrong. I need to find that article...
  • 0

#8 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7118 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 08 April 2009 - 11:19 PM

No, you're also right that you're ok at 1/60th of a second. It's also a safe speed.

http://www.panavisio...kerfree60Hz.htm

"Any Shutter Angle" for those interested, would also be any shutter speed.
  • 0

#9 Peter Apt

Peter Apt

    New

  • Basic Members
  • Pip
  • 2 posts
  • Producer

Posted 12 April 2009 - 06:54 AM

If I was shooting with a Sony EX3 under 50hz lights (Australia) overcranked at 32fps (or 31) with a 1/50 shutter will I get flicker? I am going to put the overcranked footage into a 25fps timeline. Thanks
  • 0

#10 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7118 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 12 April 2009 - 09:17 AM

You'd be risking flicker:
http://www.panavisio...kerfree50Hz.htm
  • 0

#11 Peter Apt

Peter Apt

    New

  • Basic Members
  • Pip
  • 2 posts
  • Producer

Posted 12 April 2009 - 10:20 AM

You'd be risking flicker:
http://www.panavisio...kerfree50Hz.htm


Thanks Adrian, I will have to test it... I was under the impression with a cmos as opposed to film, that the shutter speed was the determining factor for flicker rather than framerate.

Cheers
  • 0

#12 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7118 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 12 April 2009 - 10:24 AM

It's true, but generally frame rate and shutter speed are linked together. it depends on your own camera, of course. If you wanted it to react as film does you'd change the shutter speed with the frame rate.. but you don't necessarily need to.
In theory, you could keep it at 1/50th to a point (50 fps perhaps) wherein you can't fit anymore frames for that rate (does that make sense).
For ~34 fps.. you might be Ok, but personally w/o testing I'd not bank on it. Thankfully all you need is a floro bulb to give it a try (though of course, the ballasts in your location will behave differently than the ballast you test, in theory).
Good Luck!
  • 0


Tai Audio

Technodolly

Broadcast Solutions Inc

FJS International, LLC

Ritter Battery

Aerial Filmworks

Glidecam

Willys Widgets

CineTape

rebotnix Technologies

The Slider

Metropolis Post

CineLab

Paralinx LLC

Rig Wheels Passport

Visual Products

Gamma Ray Digital Inc

Opal

Media Blackout - Custom Cables and AKS

Abel Cine

Wooden Camera

FJS International, LLC

Paralinx LLC

Rig Wheels Passport

Visual Products

rebotnix Technologies

The Slider

Gamma Ray Digital Inc

CineLab

CineTape

Technodolly

Willys Widgets

Abel Cine

Broadcast Solutions Inc

Aerial Filmworks

Glidecam

Tai Audio

Opal

Wooden Camera

Metropolis Post

Media Blackout - Custom Cables and AKS

Ritter Battery