Jump to content


Photo

Diffusion Transmission with the Sun vs Lights


  • Please log in to reply
3 replies to this topic

#1 Ryan Emanuel

Ryan Emanuel

    New

  • Basic Members
  • Pip
  • 7 posts
  • Other

Posted 16 April 2017 - 02:06 PM

I've noticed that the when I set diffusion frames to diffuse the sun, they take away way more light then when I put them in front of a light.  Is that because of an inverse square thing?


  • 0


#2 Stuart Brereton

Stuart Brereton
  • Basic Members
  • PipPipPipPip
  • 2907 posts
  • Cinematographer
  • Los Angeles

Posted 16 April 2017 - 02:31 PM

The transmission characteristics of diffusion materials are a constant. They don't change depending on the light being put through them. For instance, LEE 416 has a 50% transmission, so it loses 1 stop of light. This will be the same regardless of whether it is diffusing the sun or a lamp.


  • 0

#3 Mark Kenfield

Mark Kenfield
  • Basic Members
  • PipPipPipPip
  • 1002 posts
  • Cinematographer
  • Australia/Wherever The Wind Takes Me

Posted 17 April 2017 - 08:06 AM

I think what you're seeing Ryan, is simply the same amount of diffusion, but the effect looking stronger, because outdoors is a much higher contrast environment than indoors - so when you diffuse the light hitting your subject, your background looks much brighter by comparison.
  • 0

#4 Satsuki Murashige

Satsuki Murashige
  • Sustaining Members
  • 3510 posts
  • Cinematographer
  • San Francisco, CA

Posted 17 April 2017 - 04:55 PM

Also, I suppose with an overhead frame you are also taking away some ambient skylight and increasing the relative amount of ambient bounce fill from below.

Outdoors at midday, there's literally bounce fill coming from everywhere, even if if our eyes can't normally see it since it's overpowered by direct sunlight. Take that direct source away and suddenly it's a lot more apparent. So you definitely feel the directional change of light more than if you were diffusing from the side.
  • 0


Technodolly

Glidecam

Media Blackout - Custom Cables and AKS

Gamma Ray Digital Inc

Broadcast Solutions Inc

Tai Audio

Willys Widgets

CineTape

The Slider

Aerial Filmworks

Ritter Battery

rebotnix Technologies

Paralinx LLC

Rig Wheels Passport

Metropolis Post

FJS International, LLC

Visual Products

CineLab

Abel Cine

Technodolly

Tai Audio

CineLab

Media Blackout - Custom Cables and AKS

Rig Wheels Passport

Gamma Ray Digital Inc

Paralinx LLC

Broadcast Solutions Inc

Willys Widgets

Ritter Battery

CineTape

Glidecam

Visual Products

FJS International, LLC

Metropolis Post

rebotnix Technologies

Abel Cine

Aerial Filmworks

The Slider