The Watkins Bee Exposure Meter
Specification
Instructions
Overview
The instrument indicates the correct camera exposures under all conditions for photographic plates. The basis is an actual test of the light by the sensitive paper loaded into the meter. This one test takes the place of previous elaborate calculations based on time of day, time of year, position of subject and state of weather used in other exposure calculators of the day.
Three conditions or factors have to be taken into consideration and a number or value assigned to each; they are :-
- PLATE-The Sensitiveness of the plate
- STOP-The diaphram or stop used
- Light-The actinic force of the light falling on the subject
Test the light
Hold the meter to face the source of light that falls on the subject. Revolve the back lid of the meter to expose a fresh surface of light sensitive paper through the left hand semi-circular aperture in the lower part of the dial. At the same time count "nought" and continue counting "one", "two" etc in seconds. The number of seconds for the paper to darken to the standard tint in the right hand semi-circular part of the aperture is the actinometer value.
Calculate exposure
Hold the meter by the handle in left hand and with the right thumb over the centre of the glass and fingers over the back. Grip the glass and the back firmly together and in this way the scales easily revolve together with the paper and the back. Look at the lefthand side of the meter, and by revolving the glass, set the diaphram you are using (in the column over STOP) against the plate speed (in the column over PLATE).
Take the thumb away and look out the actinometer number in the column over LIGHT, against this will be found on the outer scale, the correct exposure to give.
Note: Taken from the manual - Simple! 😂😂😂Actual manual can be seen here:- Watkins Bee Exposure Meter