Jump to content


Photo

Infrared filter?


  • Please log in to reply
4 replies to this topic

#1 Rhys Cooper

Rhys Cooper
  • Basic Members
  • PipPip
  • 26 posts
  • Student

Posted 08 April 2009 - 05:55 AM

What exactly do infrared filters do? How do they work?

How could we use them for film?
  • 0

#2 Michael Kubaszak

Michael Kubaszak
  • Basic Members
  • PipPipPip
  • 207 posts
  • 1st Assistant Camera
  • Chicago

Posted 08 April 2009 - 08:18 AM

they filter out infrared light. there is no use for them on film. they are used primarily on the RED.
  • 0

#3 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 08 April 2009 - 12:12 PM

One kind of infrared filter, as Michael says, is designed for filtering out unwanted IR spectrum light. This is usually what's meant in motion picture work and the RED has made them much more common due to the requirement for so much ND for exteriors. ND is neutral for visible light but doesn't do so well for IR spectrum so you end up unevenly filtering more visible light than IR.

There is another kind of filter commonly called an IR filter filters out everything except deep red and IR spectrum and is used for infrared shooting. I assume that's not whta you're talking about, though.
  • 0

#4 Jamie Metzger

Jamie Metzger
  • Basic Members
  • PipPipPipPip
  • 773 posts
  • Cinematographer
  • San Francisco

Posted 08 April 2009 - 12:44 PM

One kind of infrared filter, as Michael says, is designed for filtering out unwanted IR spectrum light. This is usually what's meant in motion picture work and the RED has made them much more common due to the requirement for so much ND for exteriors. ND is neutral for visible light but doesn't do so well for IR spectrum so you end up unevenly filtering more visible light than IR.

There is another kind of filter commonly called an IR filter filters out everything except deep red and IR spectrum and is used for infrared shooting. I assume that's not whta you're talking about, though.


I wish I had them on a recent shoot. Outdoors, I was pusing the Kelvin to 10,000, and the image was still looking purple, especially in the clothes of the actor.
  • 0

#5 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 08 April 2009 - 01:22 PM

I wish I had them on a recent shoot. Outdoors, I was pusing the Kelvin to 10,000, and the image was still looking purple, especially in the clothes of the actor.


Yikes, that's no good. Completely on the other side of the spectrum, I did a feature with the red in October and we got an IR filter and only used it a couple of times.
  • 0


Broadcast Solutions Inc

FJS International, LLC

Ritter Battery

Rig Wheels Passport

Wooden Camera

Visual Products

rebotnix Technologies

CineTape

The Slider

Abel Cine

Gamma Ray Digital Inc

Metropolis Post

Tai Audio

Technodolly

Media Blackout - Custom Cables and AKS

Willys Widgets

Aerial Filmworks

CineLab

New Pro Video - New and Used Equipment

Glidecam

Paralinx LLC

rebotnix Technologies

CineTape

Abel Cine

Visual Products

Ritter Battery

The Slider

Media Blackout - Custom Cables and AKS

Aerial Filmworks

Metropolis Post

Tai Audio

Technodolly

Paralinx LLC

FJS International, LLC

Gamma Ray Digital Inc

CineLab

Willys Widgets

Wooden Camera

Broadcast Solutions Inc

New Pro Video - New and Used Equipment

Glidecam

Rig Wheels Passport