Kaufmann's wonderful Posographe
Kaufmann’s Posographe is nothing less than an analog
mechanical computer for calculating six-variable functions.
Specifically, it computes the exposure time (Temps de Pose) for
taking photographs indoors or out (depending on which side you use).
The input variables are set up on the six small pointers; the large
pointer then gives you the correct time. The variables are very
detailed, yet endearingly colloquial. For outdoors, they include the
setting -- with values like “Snowy scene”, “Greenery with expanse of
water”, or “Very narrow old street”; the state of the sky --
including “Cloudy and somber”, “Blue with white clouds”, or “Purest
blue”; The month of the year and hour of the day; the illumination
of the subject; and of course the aperture (f-number).
MORE
Kaufmann’s Posographe is nothing less than an analog
mechanical computer for calculating six-variable functions.
Specifically, it computes the exposure time (Temps de Pose) for
taking photographs indoors or out (depending on which side you use).
The input variables are set up on the six small pointers; the large
pointer then gives you the correct time. The variables are very
detailed, yet endearingly colloquial. For outdoors, they include the
setting -- with values like “Snowy scene”, “Greenery with expanse of
water”, or “Very narrow old street”; the state of the sky --
including “Cloudy and somber”, “Blue with white clouds”, or “Purest
blue”; The month of the year and hour of the day; the illumination
of the subject; and of course the aperture (f-number).
MORE
