The next requirement is flash of high power.

Rules that apply to the use of flash and many flash units used for lighting a single frame picture.

Rules of Flash Power for Single Frame Pictures

Rule 1 The light from the flash dissipate at the rate of 1/(distance)*(distance). Another way to look at it is that twice the distance away the light drops off -2 stops, or 1/2 the distance away +2 stops increase in light on the subject.

Rule 2. Is that the light on the subject from the flash sets the available light for the picture. The camera to the subject distance changes the subject size on the negative only.

Rule 3. Is move the flash units in as close as permitted. For each halving in distance there is +2 stop gain in flash power on the subject. If the field of view is very small, adjust the distance for correct film exposure.

Rule 4. Is that one flashing of the flash unit equals reference power found in a single flash table. Two flashings equals twice the power or +1 stops over reference value. Four flashings equal 4 times the power or +2 stops. Eight flashings equals 8 times the power or +3 stops. Sixteen flashings equal 16 times the power or +4 stops. With this translates into one sixty watt-second flash on manual for full power out as a Vivitar 283 or 285 can deliver 480 watt-seconds for the picture, if fired 16 times. Note! The total time for this picture should take about 90 seconds (to pervent overheating the flash unit), but due to the high f-stop used the film only sees the flash duration, therefore the total exposure is 16/1,000 of a second for mono fireing of the flash unit(s). Two flash units would take 8 flashings for the same total power and total exposure, if fired at the same time would be 8/1,000 of a second. This total short flash present duration allows for color as well as black and white film.