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
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|