Kevin the answer to your question is in Harold Edgerton's book "Electronic Flash, Strobe" MIT Press. ISBN 0-262-55014-8 Flash duration is a complex subject it is measurable and is a function of capacitance and voltage. Voltage and its duration are easily measured with an oscilloscope. T=RC/2 T=time (microseconds) C=capacitance in farads R=E/Imax R=resistance E=initial capacitor voltage Imax=Peak discharge current
To use this formula we would need to know the specification of the flash lamp. All this and everything you will probably like to know about high speed light sources, and its application to photography is in this book. This is a complex subject which Edgerton passionately studied, and developed practical applications. He shared his knowledge with any body that graced his door, and he has left us a great legacy in his book. Jonathan -----Original Message----- From: Kevin Waterson [mailto:[EMAIL PROTECTED] Sent: Saturday, December 11, 2004 4:33 AM To: [EMAIL PROTECTED] Subject: flash duration Is it possible to measure the duration of a flash? Possibly in micorseconds or something? Kind regards Kevin -- "Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote."