At 12:51 PM 10/22/2001, you wrote: > they quote power is w/s. I am trying to >figure out how that compares to guide numbers and specifically to 550ex >power. Or are they comparable?
They're not, really. It's like comparing horsepower to mpg in a car. W/S = Watt/Seconds and measures the quantity of electricity produced by a capacitor (which is the thing which whistles when you flash is recharging). Guide Number is a measure of the amount of illumination the head produces and is determined by w/s, the size of the flash tube, the shape & surface of the reflector and its position in relationship to the flashtube.. Hope thios helps. -- regards, Henry Posner Director of Sales and Training B&H Photo-Video, and Pro-Audio Inc. http://www.bhphotovideo.com * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
