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Re: filmscanners: was:(OT) Pixels per inch vs DPI now: flash synch speeds
I believe most studio flash systems are considerably brighter than
camera mounted portable flashes, and this might explain the differences.
I wasn't aware, since I do not use studio flash, that they could be so
long. I suspect if the average hand held/camera mounted electronic
flash had that long a flash period, with the same guide number, the
batteries would be gone in no time.
SKID Photography wrote:
> For the record, we use ProFoto studio lights, where we've experienced
> the 250th of a second cut off of lighting output on our Polaroids.
> Harvey Ferdschneider
> partner, SKID Photography, NYC
> RogerMillerPhoto@aol.com wrote:
> The Speedotron Black Line 2400 watt-second has a flash duration of
> 1/300th second, and shorter if you dial down the power. That's
> typical of studio power packs. That duration is measured between
> the 10 percent points. I'm not sure why you'd care about latency (I
> have to admit I haven't been following this off-topic discussion
> closely). Latency (the time lag it takes for the light out put to
> reach 10 percent of its peak) should be measured in microseconds
> rather than milliseconds and should rarely be of concern.
> In a message dated 10/31/2001 3:56:05 PM Pacific Standard Time,
> firstname.lastname@example.org writes:
> > I thought the longest flash durations were in the
> neighborhood of
> > 1/500th sec. I don't recall seeing exposure differences at
> > speeds 1/250 or slower where ambient light isn't a factor.
> It takes "some" time for the flash to actually fire...and I
> would also guess
> different types of flashes have different timing (latency).
> Does anyone
> actually know what a typical flashes latency time is?
> I can check my Elinchroms to see what they say this time is
> supposed to
> be...as I have the service manuals for them, and they are pretty
> comprehensive...hopefully, they'll have something to say about it.