Paul C. Buff, Inc. Technical Forum

Is there an easy way to convert wattseconds to lumen?

Or some other conversion that could equate the light output to a continuous light source.

I am constantly asked to compare the output of the flash to a regular light bulb. I need a simple analogy to explain this to non-photographers.

Any suggestion would be appreciated.


Thanks

The maximum practical efficacy of Xenon tubes is about 45 lumenseconds per WS. Our lights achieve that. So our 640WS yields about 29,000 Lumenseconds.

An incandescent lamp gives about 20 lumens per watt. So a 500W lamp yields about 10,000 lumens. About equal to the exposure of a 640WS flash . . . if you expose at about 2.8 seconds with the incandescent. At 1/500 second exposure you'll need about 500,000W incandescent. This is quick mental math so may be a bit off.

thanks