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<blockquote data-quote="WayneF" data-source="post: 385815" data-attributes="member: 12496"><p>There probably are some marketing words, but he is speaking of 1/2,000,000 seconds duration, and I think 500 volts simply will not do it. I don't know what a price would be, but it will cost more and be more dangerous than speedlights.</p><p></p><p>Nikon speedlights run about 320 volts on the capacitor. They contain such a power converter that runs on the AA batteries (the recharge whine we hear). The external battery packs are similar (maybe larger) power converters outputting this 320 volts directly to the capacitor, for faster recycle. Either way, the capacitor voltage is what it is.</p><p></p><p>Monolights may be 500 volts (AB is), and typically turn the voltage down to decrease their power level. Easy, but this lower voltage typically slows them down to a longer about 2x duration (less power to push them)... and makes the flash be more red color.</p><p></p><p>Speedlights always trigger at the one full voltage, and then their duration is cut off, quenched to stop it, to provide a shorter flash at less power rating. These become more blue at low power, by cutting off the trailing low power decay tail. At 1/128 power,the SB-910 spec is 1/38,500 second duration. That is not in the same class as 1/2,000,000 second. </p><p></p><p>Speaking of flash tubes instead of LEDs, my notion is that to have any usable amount of light output at 1/2,000,000 second duration, we are going to have to start at a much higher power level. I think we are speaking of thousands of volts (for flash tubes).</p><p></p><p>You can read about <a href="http://en.wikipedia.org/wiki/Flashtube#History" target="_blank">Harold Edgerton</a>, who basically invented the flash tube in the late 1920s. He began with spark gaps, and then xenon flash tubes, specifically meaning high speed flash then, and he did the first milk drop splashes, etc (then he and his work were later on very important in the WWII effort). He had no thyristors yet, but he was using 5000 volts on the capacitors. I would call that dangerous.</p><p></p><p>One can seriously be hurt in a speedlight if they open the case and prowl around. A capacitor is not limited in the current it delivers. Flash tubes operate around 2400 amps/per sq cm area (term is current density), which is what ionizes the xenon gas. The flash dumps a capacitor energy charge of maybe 75 to 2400 watt seconds nearly instantaneously.</p></blockquote><p></p>
[QUOTE="WayneF, post: 385815, member: 12496"] There probably are some marketing words, but he is speaking of 1/2,000,000 seconds duration, and I think 500 volts simply will not do it. I don't know what a price would be, but it will cost more and be more dangerous than speedlights. Nikon speedlights run about 320 volts on the capacitor. They contain such a power converter that runs on the AA batteries (the recharge whine we hear). The external battery packs are similar (maybe larger) power converters outputting this 320 volts directly to the capacitor, for faster recycle. Either way, the capacitor voltage is what it is. Monolights may be 500 volts (AB is), and typically turn the voltage down to decrease their power level. Easy, but this lower voltage typically slows them down to a longer about 2x duration (less power to push them)... and makes the flash be more red color. Speedlights always trigger at the one full voltage, and then their duration is cut off, quenched to stop it, to provide a shorter flash at less power rating. These become more blue at low power, by cutting off the trailing low power decay tail. At 1/128 power,the SB-910 spec is 1/38,500 second duration. That is not in the same class as 1/2,000,000 second. Speaking of flash tubes instead of LEDs, my notion is that to have any usable amount of light output at 1/2,000,000 second duration, we are going to have to start at a much higher power level. I think we are speaking of thousands of volts (for flash tubes). You can read about [URL="http://en.wikipedia.org/wiki/Flashtube#History"]Harold Edgerton[/URL], who basically invented the flash tube in the late 1920s. He began with spark gaps, and then xenon flash tubes, specifically meaning high speed flash then, and he did the first milk drop splashes, etc (then he and his work were later on very important in the WWII effort). He had no thyristors yet, but he was using 5000 volts on the capacitors. I would call that dangerous. One can seriously be hurt in a speedlight if they open the case and prowl around. A capacitor is not limited in the current it delivers. Flash tubes operate around 2400 amps/per sq cm area (term is current density), which is what ionizes the xenon gas. The flash dumps a capacitor energy charge of maybe 75 to 2400 watt seconds nearly instantaneously. [/QUOTE]
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