Jump to content


Photo

Tri-X Reversal ASA


  • Please log in to reply
3 replies to this topic

#1 Renny McCauley

Renny McCauley
  • Basic Members
  • PipPip
  • 21 posts
  • Student

Posted 01 November 2008 - 02:09 PM

This is probably a stupid question, but I was looking at the ASA ratings for Tri-X 16mm reversal film. Kodak seems to list a tungsten rating (160) and a daylight rating (200). Why are there two different ratings? It looks like all the b&w stocks are like that, but not the color stocks. Thanks for the help.

Renny
  • 0

#2 Adrian Sierkowski

Adrian Sierkowski
  • Sustaining Members
  • 7375 posts
  • Cinematographer
  • Los Angeles, Ca

Posted 01 November 2008 - 03:22 PM

It has to do with the sensitivity of parts of the emulsion to differing parts of the visual light spectrum; notably blue and red. It's more sensitive to blue; hence the faster speed in daylight, than it is to red. This is true of B/w film only. Color film is balanced for certain color temperatures and it's EI based on that.
  • 0

#3 Charles MacDonald

Charles MacDonald
  • Sustaining Members
  • 1157 posts
  • Other
  • Stittsville Ontario Canada

Posted 01 November 2008 - 05:40 PM

Color film is balanced for certain color temperatures and it's EI based on that.

If you want to shoot colour film at other temperatures, ie daylight film undertungsten, the label doestwll you what EI ot start with with the corection filter. Thew filters are not needed for B&W hence the instuctions focus on the light itelf.
  • 0

#4 Renny McCauley

Renny McCauley
  • Basic Members
  • PipPip
  • 21 posts
  • Student

Posted 01 November 2008 - 07:53 PM

It has to do with the sensitivity of parts of the emulsion to differing parts of the visual light spectrum; notably blue and red. It's more sensitive to blue; hence the faster speed in daylight, than it is to red. This is true of B/w film only. Color film is balanced for certain color temperatures and it's EI based on that.

Okay, that makes perfect sense. I figured this was a simple question. Thanks,
Renny
  • 0


Media Blackout - Custom Cables and AKS

Ritter Battery

New Pro Video - New and Used Equipment

Aerial Filmworks

rebotnix Technologies

Technodolly

Rig Wheels Passport

Wooden Camera

The Slider

Broadcast Solutions Inc

Visual Products

Metropolis Post

Tai Audio

CineLab

Glidecam

CineTape

FJS International, LLC

Paralinx LLC

Abel Cine

Willys Widgets

Gamma Ray Digital Inc

Rig Wheels Passport

Ritter Battery

Metropolis Post

Technodolly

Visual Products

New Pro Video - New and Used Equipment

CineTape

Abel Cine

Gamma Ray Digital Inc

Tai Audio

rebotnix Technologies

Wooden Camera

Media Blackout - Custom Cables and AKS

Glidecam

The Slider

FJS International, LLC

CineLab

Paralinx LLC

Willys Widgets

Aerial Filmworks

Broadcast Solutions Inc