Jump to content


Photo

Polarised light sources?


  • Please log in to reply
4 replies to this topic

#1 Karel Bata

Karel Bata
  • Basic Members
  • PipPipPipPip
  • 487 posts
  • Director
  • London - a rather posh bit

Posted 25 July 2011 - 04:07 AM

Are there any light sources, powerful enough to light with, that are polarised? Do such things exist? Or any way of polarising a regular source these days I'm unaware of?

It's an odd question I know. I've noticed that my computer display is heavily polarised, as is my phone and iPod, but is there anything usable for cinematography?

Cheers! :D
  • 0

#2 Paul Brenno

Paul Brenno
  • Basic Members
  • PipPipPip
  • 118 posts
  • Cinematographer
  • North Dakota

Posted 25 July 2011 - 12:05 PM

Karel, what effect or what do you mean by polarizing lighting ???
there are polarizing filters, which take out the glare/reflections and deepen blue in the sky, but what are you trying to do with the lighting ???
thanks, Paul
  • 0

#3 John Sprung

John Sprung
  • Sustaining Members
  • 4635 posts
  • Other

Posted 26 July 2011 - 04:33 PM

Certainly any source can be filtered to get polarized light. I don't know of any that are inherently polarized. Specular reflections are more polarized the sharper the angle -- like the headlights of a distant car kicking off wet pavement. The daytime sky is a polarized source, which is why you can darken it with a polarizing filter.

By polarizing at the source, I suppose you could control the specular kicks of some sources differently than others. Other than that, why would you want a polarized source?





-- J.S.
  • 0

#4 Martin Hong

Martin Hong
  • Basic Members
  • PipPipPip
  • 137 posts
  • Student

Posted 27 July 2011 - 01:29 AM

You mean something like this?

http://www.bhphotovi...ow_Film_56.html

Edited by Martin Hong, 27 July 2011 - 01:32 AM.

  • 0

#5 Karel Bata

Karel Bata
  • Basic Members
  • PipPipPipPip
  • 487 posts
  • Director
  • London - a rather posh bit

Posted 27 July 2011 - 07:55 AM

Sorry for my delay in replying.

My query came out of a discussion elsewhere about the issues surrounding the selective filtering of polarised light in 3D mirror rigs leading to retinal rivalry in the two cameras. One solution gaining ground is the use of a 1/4 wave retarder over the whole front of the box, but it made me wonder if there were any other less obvious solutions. I'd been taken by surprise a while back to discover that flat screen displays are heavily polarised, so I wondered if there might be light sources that were polarised too that I was unaware of.

Had that been the case I'm not sure how it might have been used practically, but it would have been an interesting line of enquiry.

Worth asking anyhows I thought. Always keen to learn.

I like the huge polarising sheet of plastic! Bit expensive though.

Cheers! ;)
  • 0


Tai Audio

Wooden Camera

Abel Cine

Broadcast Solutions Inc

rebotnix Technologies

FJS International, LLC

Technodolly

Metropolis Post

Paralinx LLC

Willys Widgets

Media Blackout - Custom Cables and AKS

Aerial Filmworks

Gamma Ray Digital Inc

Ritter Battery

Opal

Rig Wheels Passport

Visual Products

Glidecam

The Slider

CineLab

CineTape

Willys Widgets

Paralinx LLC

Rig Wheels Passport

Ritter Battery

The Slider

Gamma Ray Digital Inc

Opal

CineTape

Tai Audio

Abel Cine

FJS International, LLC

Technodolly

Wooden Camera

rebotnix Technologies

CineLab

Metropolis Post

Broadcast Solutions Inc

Glidecam

Aerial Filmworks

Media Blackout - Custom Cables and AKS

Visual Products