Sheesh! Fire the flash, chimp the histogram, tweak the aperture. Done!
Dr. Flash
Piers Hemy wrote:
> 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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