Flash Charts for PinPLUS Cameras
To find the watt-seconds of a flash unit.

There are two ways. One is to set the dial for finding the f-stop on the flash unit to ASA 400 then at 10 foot mark find the f-stop. Note this f-stop can be +/- 1 stop for true output power. Using this f-stop go to next paragraph. The second and most accurate way is to use a flash meter at 10 feet, centered on the flash unit being tested. Set the flash meter for ASA 400 film. Fire the flash looking at the flash meter. The meter f-stop reading is the amount of light that the flash unit can put on a subject at 10 feet. Using this f-stop go to next paragraph.

On the ASA 400 chart find the f-stop that was from dial or flash meter. In columns 2-10 find the bold maroon number 10 [this is 10 foot distance for subject to flash in the chart]. Run the eye to the top of the column this value is the number of watt-seconds the flash you have available.