My mind is in La La land right now, so I wanted to ask you high-techie photogs to verify something for me.
Simply stated, under the Inverse Square Law, if your light meter measures F/11 when your studio light source is five feet from your subject
, by moving the light 10 feet (twice the distance from your subject), you’ve reduced the light by one-quarter of its power, or two full F/stops.
Remember, every time you decrease an F/stop, you have a 50-percent light increase, so from F/11 to F/8 is a 50-percent light increase and from F/8 to F/5.6 is another 50-percent light increase, or 4-times the original light at F/11.
Comments? Thanks, rg sends!