View Full Version : Extinction Meters

3-Jan-2017, 21:56
My attention has turned to early light meters, such as extinction meters. How commonly used were they? How accurate--I'm guessing maybe about a stop once you've figured them out? Fairly reliable? What were the better ones 1900-1940? I have a Zeiss Diaphot I've been playing around with. I like its slim form, and so far I seem to be getting a usable reading from it (within a stop) about ~two thirds of the time.

Kent in SD

3-Jan-2017, 22:16
I got into extinction meters in a big way about twenty years ago. To me it was a fascinating entry into the idea. Unfortunately the materials of the meters faded away, quite literally, so all I have are a bunch of 'dumb tubes', which is no fault of the inventors.

I did find a fascinating alternative. It was so simple. It was a card with images of the human iris, with a narrow mirror below it, and below that a print of f-stops below each.

The idea was for the person to match his iris to the table to determine the appropriate f-stop.

An ingenious idea - discounting our great differences in light response, and in my area of differences before and after a heavy New Years celebration. :)

3-Jan-2017, 22:22
I've wanted to buy one of the Zeiss Diaphots just for the coolness factor. Such a neat little piece of kit!
Edit: Dang it, I just bought one. ;-)

4-Jan-2017, 03:38
The Diaphot seems to rely on inert colored glass (blue.) Doesn't that make it more immune to the problem of fading ink on the other designs?

Kent in SD

Jim Jones
4-Jan-2017, 07:11
Relating film exposure to the iris diameter has only up to a four stop exposure range. However, many years someone reported in a photography magazine that setting his camera iris to the width of the iris in his cat's eye was reliable. An exposure meter would have been more convenient on photo expeditions.

4-Jan-2017, 07:59
Extinction meters!?!! The name says it all... Extinct... Just for daylight use, where sunny-16 would also work too...
(Try using one for a night shot...) :-(

The first Weston meter was a revolution in photography... Photogs usually developed their own instincts to proper exposure based on a good eye, and many tests... I think Ansel got very excited when first using one, and I believe that he extended the U & C (underexposed & contrast) settings on the exposure pointer further to start creating the Zone System... I think that this meter might have been the germ of the idea of it... I had heard that E Weston (no relation) admired it, but knew how to expose already, so passed on using one...

Steve K

4-Jan-2017, 09:56
With that pentagram on top you do look kinda cool :-D

Mark Sampson
4-Jan-2017, 16:17
"Photography made difficult". That's the name of a college course taught by W. Eugene Smith late in his life, but it applies here as well. I think you'd be better off using a Kodak Master Photoguide.

4-Jan-2017, 16:38
"Photography made difficult". That's the name of a college course taught by W. Eugene Smith late in his life, but it applies here as well. I think you'd be better off using a Kodak Master Photoguide.

Possibly. I am exploring "authentic" ways to make photos, c.1910 (plus or minus a decade.)

Kent in SD

Mark Sampson
4-Jan-2017, 18:32
I would imagine that there were similar, if less comprehensive, printed guides to exposure that far back. I'd search the literature... Kodak was of course offering instruction from the very beginning. Remember that exposure was less critical when film was ortho-sensitive at best and development was by inspection under a red light. Plus the albumen, printing-out, and 'gaslight' papers in use then were low in contrast and required a contrasty or 'plucky' negative... so the precision required with modern materials was not as necessary. You might also contact Mark Osterman at the George Eastman Museum. He's made a career of pre-WW2 photography practice, teaches many of the old techniques, and is a nice guy to boot.

Kevin Crisp
4-Jan-2017, 18:59
Just an observation...if you keep exposure records, sometime go back through a few years of them. You might be amazed at how many times your exposure is....the same.