Hmmm
Your memory is clearly better than my ability to enter numbers on my
phone calculator. Seems I hit Sqrt(320) rather than sqrt(32). Bah. At
least thte formula was OK.
Further need to revise my post from the flash being a fusion reactor at
that ISO to fission reactor. Still seems useful to know the approximate
range at a given aperture by doing the calculation. When confronted
with a Moose-like function with G9, put the thingie on manual on
slowest speed I think wil be OK. FEC at -1 or so and chimp. The ETTL
business isn't horrible most of the time. The T32 with Stoffen thingie
works well on the G9, but the auto modes aren't flexible enough if the
ISO is raised. ( Still can't find the GN/joules on the G11--someone
should put it on full dump and measure it.)
An embarassed student of Dr. Flash,
Mike
Dr Flash must be occupied elsewhere, Mike, otherwise he would surely
have
clarified the GN for you.
If *my* memory serves if GN is 9 at ISO100, it should be approx. 50 at
ISO3200.
GN = f/stop * flash-to-subject distance
Thus for GN 9 at ISO100, use f/2 at 4.5m
Amend ISO to 3200, gain 5 stops, use f/11 at 4.5m
11 * 4.5 = 49.5, being GN for ISO3200
But then, sqrt (3200/100) is greater than 5 but less than 6, thus
9*sqrt(3200/100) is likely to give the same answer ... if computed
correctly
:-)
Piers
-----Original Message-----
From: usher99@xxxxxxx [mailto:usher99@xxxxxxx]
Sent: 17 December 2009 18:02
To: olympus@xxxxxxxxxxxxxxxxx
Subject: [OM] OT: G11 review [wasBefore you go, Moose ...]
Welcome back, thanks for the few shots. I wouldn' t have dared ISO
3200 on
the G9. Your shots demonstarate well that high ISO turns a
baby flash into a fusion reactor equivalent at base ISO. Let's see,
can't really find the GN for the G11???? I think the G9 is in the
neighborhood of 9 ( m,ISO 100); so if memory serves that would be 9 *
sqrt(3200/100)--approx 160!!!
--ытшз
--
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