Jump to content


Photo

Reflected Light Readings


  • Please log in to reply
3 replies to this topic

#1 Stephen Whitehead

Stephen Whitehead
  • Basic Members
  • PipPipPip
  • 124 posts
  • Cinematographer
  • Toronto, Canada

Posted 07 May 2007 - 09:02 PM

Hey, this is just a simple question of semantics. A reflected light reading is taken from a spot meter right? The reason I ask is just in regards to the kodak exposure examples which are given in reflected light readings. On the 5212 example the white sheets on the bed are listed as +3.3 stops. Does this take into consideration the inherent white tone of the sheets, or is this merely the intensity of light hitting that surface?

Check it out for yourself: http://kodak.com/US/...g....12.6&lc=en

Cheers,

Steve
  • 0

#2 Chris Keth

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

Posted 07 May 2007 - 09:39 PM

Hey, this is just a simple question of semantics. A reflected light reading is taken from a spot meter right? The reason I ask is just in regards to the kodak exposure examples which are given in reflected light readings. On the 5212 example the white sheets on the bed are listed as +3.3 stops. Does this take into consideration the inherent white tone of the sheets, or is this merely the intensity of light hitting that surface?

Check it out for yourself: http://kodak.com/US/...g....12.6&lc=en

Cheers,

Steve


They're done with a calibrated spotmeter. It's the simplest and most helpful reading they could give you since you don't have to know anything about the surface being lit. If they gave you an incident light reading for specific areas, you would technically have to know the reflectance of that surface to have useful information.
  • 0

#3 Stephen Whitehead

Stephen Whitehead
  • Basic Members
  • PipPipPip
  • 124 posts
  • Cinematographer
  • Toronto, Canada

Posted 07 May 2007 - 09:46 PM

They're done with a calibrated spotmeter. It's the simplest and most helpful reading they could give you since you don't have to know anything about the surface being lit. If they gave you an incident light reading for specific areas, you would technically have to know the reflectance of that surface to have useful information.


So then if you put a grey card onto the same spot where they took the reading of the white bed sheet, the reading would be a few stops lower?
  • 0

#4 Jake Kerber

Jake Kerber
  • Basic Members
  • PipPip
  • 65 posts

Posted 08 May 2007 - 10:51 AM

The Kodak photo lists a taking stop of T2.8, so all of those meter readings are in reference to that stop. And a light meter is calibrated to give you correct exposure of an 18% middle grey card, so readings need to be interpreted as such. For instance, if you take a reading of the white bedsheet and the meter says F11, but you know that the zone that you want that sheet to fall in is about 4 stops up the scale (zone iX/white), you would set your stop at T2.8 and know the bedsheet will look white. Of course, when using a spot meter you are inevitably going to read the entire scene before you roll and make sure everything in the frame is reading where you want it--face of subject, shadow areas, back wall, window with view to the outside, white bedsheet, etc.

-Michael Jacob Kerber
D.P.
L.A.
  • 0


Paralinx LLC

Metropolis Post

Glidecam

CineTape

Ritter Battery

Media Blackout - Custom Cables and AKS

The Slider

FJS International, LLC

rebotnix Technologies

Rig Wheels Passport

Gamma Ray Digital Inc

Abel Cine

Willys Widgets

Wooden Camera

Visual Products

Tai Audio

CineLab

Opal

Broadcast Solutions Inc

Aerial Filmworks

Technodolly

The Slider

rebotnix Technologies

Tai Audio

Visual Products

Wooden Camera

Willys Widgets

CineTape

Glidecam

Rig Wheels Passport

CineLab

Ritter Battery

Aerial Filmworks

FJS International, LLC

Metropolis Post

Media Blackout - Custom Cables and AKS

Broadcast Solutions Inc

Technodolly

Paralinx LLC

Opal

Gamma Ray Digital Inc

Abel Cine