Jump to content


Photo

Exposure Adjustment For Filters


  • Please log in to reply
4 replies to this topic

#1 Ira Ratner

Ira Ratner
  • Basic Members
  • PipPipPipPip
  • 558 posts
  • Other
  • Coral Springs, Florida

Posted 10 November 2008 - 08:06 AM

I just ordered polarizing, red and yellow Cokin clone filters for b&w shooting. Since they're not Cokin brand, and I'm not metering through the lens, can I assume that my exposure compensations will be equal to the Cokins?

Yeah, I should have bought the Cokins, but there's no one on eBay selling them. And yeah again, I could ask the seller, but I'd rather ask for your input first.

Here's the red one:

http://cgi.ebay.com/...em=290018800609

And the Polarizer:

http://cgi.ebay.com/...em=290018800609
  • 0

#2 David Rakoczy

David Rakoczy
  • Basic Members
  • PipPipPipPip
  • 1579 posts
  • Cinematographer
  • USA

Posted 10 November 2008 - 08:48 AM

The only way to tell (short of contacting the Manufacturer) is to Spot Meter thru the Filter and compare that to what you get Spot Metering the same object (e.g. Gray Card) without the Filter.

Edited by David Rakoczy, 10 November 2008 - 08:49 AM.

  • 0

#3 Ira Ratner

Ira Ratner
  • Basic Members
  • PipPipPipPip
  • 558 posts
  • Other
  • Coral Springs, Florida

Posted 10 November 2008 - 05:35 PM

The only way to tell (short of contacting the Manufacturer) is to Spot Meter thru the Filter and compare that to what you get Spot Metering the same object (e.g. Gray Card) without the Filter.


Uhhh...

Thanks for reminding me of what an idiot I am, Dave.

Am I THAT old that I couldn't figure that out for myself?

Yes.
  • 0

#4 Chris Keth

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

Posted 10 November 2008 - 08:25 PM

Uhhh...

Thanks for reminding me of what an idiot I am, Dave.

Am I THAT old that I couldn't figure that out for myself?

Yes.


It was early in the morning. Anyway, make sure it is a neutral surface you spotmeter. Lightmeters don't generally have perfectly even spectral sensitivity. I don't know that it's enough variation to throw your exposure off enough to matter but I like to be thorough when I do that kind of thing.
  • 0

#5 Simon Wyss

Simon Wyss
  • Basic Members
  • PipPipPipPip
  • 1491 posts
  • Other
  • Basel, Switzerland

Posted 11 November 2008 - 05:09 AM

Since the test method for filter density is so simple you can readily rely on manufacturers' data unless they are false.
  • 0


Paralinx LLC

Visual Products

Gamma Ray Digital Inc

FJS International, LLC

Technodolly

Metropolis Post

Glidecam

Abel Cine

Media Blackout - Custom Cables and AKS

Wooden Camera

New Pro Video - New and Used Equipment

Rig Wheels Passport

Ritter Battery

rebotnix Technologies

Aerial Filmworks

CineTape

CineLab

Tai Audio

The Slider

Broadcast Solutions Inc

Willys Widgets

Abel Cine

Glidecam

Willys Widgets

FJS International, LLC

New Pro Video - New and Used Equipment

Metropolis Post

Tai Audio

Gamma Ray Digital Inc

Paralinx LLC

Ritter Battery

Aerial Filmworks

rebotnix Technologies

Media Blackout - Custom Cables and AKS

Wooden Camera

Technodolly

CineTape

CineLab

Broadcast Solutions Inc

The Slider

Rig Wheels Passport

Visual Products