John_F wrote:
At a shutter speed of 1/100 sec light will travel 9,835,710.56 feet. So all that flash light can get to thr falls and get back. But the light energy absorbtion by air and water vapor wipes out the effect, Also the beam diverges going out and coming back, makes things worse. But the more you fire the flask the more you wear it out and the sooner you buy a new one. So you are helping the economy and might that not brighten any pictures.
And light dissipates proportionally to square of the distance - so a flash which produces adequate light at 20 Ft would provide 1% of that at 200 Ft - and a lot less than that at a mile.