The Posographe

[Dany]

This can be considered as one of the ancestors of the light cells used today in photography.

The "Posographe" is in fact nothing else that an analog mechanical computer able to tell you which exposure time is to be used depending on many parameters as the type of film, the available light, the diaphragm, the time of the day, the location, the type of subject etc...
Elaborated in France by Mr Kaufmann circa 1922, 1923 the Posographe measures apprx 13 x 8 cm.

The instrument shows a metal frame with sliding indexes on each four sides of the frame.
The frame is supporting two panels installed back to back. One is dedicated to outdoor photography, the second one show parameters for indoor photography.

Between these two panels, an hidden and complicated set of levers is linking the different sliding indexes.

The photographer choose the face of the instrument (indoor or outdoor), give the correct position of the different parameters indexes and read the exposure time .
I bet Mr Kaufmnn suffered a lot of headaches designing the correct form and combination of the levers. But he did it and it gives a nice example of 1920's engineering.

 

[jcdeboever]

That is way cool and very interesting.

 

[Derrel]

WAYYYYY COOL! Thanks for posting this!

I thought this type of device was sometimes called an extinction light meter.

My only experience with an even remotely similar device was on an 8mm, key-wind, Bell & Howell movie camera, which had a rotary chart on one side, consisting of lighting conditions, and winter/fall and summer/spring lighting conditions, and equatororial position, and some other longitude information, all in all probably 200 little boxes, and a few columns, and some lens f/stops,and shutter speeds that corresponded with frame rates, and the ASA speed of the movie film in use.

It worked GREAT!!!! I had no light meter, but still, the information if read correctly, gave the right f/stop for every film, at the differeing shutter speeds the B&H camera had at 16,24,32, and even its top frames per second rate of, IMMMSMC, 72 fps, for five feet of film exposed in about 5 seconds!

This type of rotary-dial extinction meter was from a 1940's Bell & Howell movie camera; I suspect that even earlier 1920's and 1930's movie cameras had similar, on-board "meters" to guide the operators in selecting the correct f/stop for the various shutter speeds of the day.

I am fascinated by the beauty of this instrument you have shown us.

 

[Ysarex]

Love it! It even has a Zones 1 - 5 (they couldn't use 10 back then).

Joe

 

[snowbear]

OK, I need one of these! Thanks for sharing.

 

[Dany]

Hi all,
Hi Derrel,

In fact extinction light meters were a bit different.
Most of them were made on the base of a small slide showing indications on a row .
Indications are made gradually darker (opaque) and the available light passing through them is observed by the photographer.
The darker indication that can be seen by the photographer gives a value that provides you the F stop and exposure time when reported on a table
These extinction meters were separate accessories or built in systems in some cameras
The French manufacturer Lumière equipped with built in extinction meters the Eljy Club and the very scarce Lumière 6x6cm (page 636 of the McKeown last edition) . The system was named "LUMIPOSE"
Here is a pic of the Lumière 6x6 from my collection together with its Lumipose extinction meter window on top of the body, close to the finder lens. The exposure table is on the inside of the camera bed, below the lens

 

[Gary A.]

A l'enfer avec Sunny 16 ... J'ai besoin d'un posographe.

 

[Derrel]

Great stuff, Daniel C! Enjoyed seeing this.

 

[Dany]

By the way, I remember that I recently discovered at the bottom of a crate a quite scarce instrument which provides a very compact combination of a range finder together with an extinction meter.
This item, called Combi Meter, is to be installed on the accessory shoe of a camera. It was manufactured in Germany by the Wata company.
This is a pic showing the front and rare side of this accessory.

 

[jcdeboever]

By the way, I remember that I recently discovered at the bottom of a crate a quite scarce instrument which provides a very compact combination of a range finder together with an extinction meter.
This item, called Combi Meter, is to be installed on the accessory shoe of a camera. It was manufactured in Germany by the Wata company.
This is a pic showing the front and rare side of this accessory.

View attachment 132407

I could use one of those on my Agfa Isollette II

Sent from my XT1254 using ThePhotoForum.com mobile app

 

[Gary A.]

By the way, I remember that I recently discovered at the bottom of a crate a quite scarce instrument which provides a very compact combination of a range finder together with an extinction meter.
This item, called Combi Meter, is to be installed on the accessory shoe of a camera. It was manufactured in Germany by the Wata company.
This is a pic showing the front and rare side of this accessory.

View attachment 132407

I could use one of those on my Agfa Isollette II

Sent from my XT1254 using ThePhotoForum.com mobile app

That was the first thing that came into my head was "JC needs one of those for his Isollette".

 

[Dany]

What a great idea JC !
I will install it on my own Isollette II
(Variation with an Apotar lens on Prontor S shutter)

 

[jcdeboever]

What a great idea JC !
I will install it on my own Isollette II
(Variation with an Apotar lens on Prontor S shutter)

View attachment 132474

Cool! There are a couple on ebay. I ended up getting a different one for $10 clams, I just need it to measure distance. I am getting pretty good at guessing exposure but still phone meter it.