[SerraAva]

Sometimes use the Pythagorean Theorem to find the throw distance of the light. Measure straight down from the light to stage level if its your target, then to where your focusing from that point. a^2 + b^2 = c^2 or (a^2 + b^2)^1/2 = c where a is your height, b is your length, and c is your throw distance. You can then multiply c by your MF to determine beam size.