I've reformatted the quoted post a bit, apologies - I hope this way my
reply will be more coherent.
On Thu, 19 Jul 2012, Chuck Norcutt wrote:
> On 7/18/2012 2:39 PM, usher99@xxxxxxx wrote:
>>
>> Super FP Flash Guide Numbers (m.) Normal "OTF" Flash Range Guide (ISO
>> 100) Super FP Flash / Range Chart
>> Shutter speed OM-707 OM-3Ti, OM-4Ti
>> 1/2000 3.1 2.6
>> 1/1000 4.3 3.7
>> 1/500 6.2 5.2
>> 1/250 8.8 7.3
>> 1/125 12.4 10.4
>> 1/100 15.6 -
>> 1/60 or slower - 14.7
>
> Nearly totally useless information. The only reason to use FP mode is
> for fill flash. The guide number table says: "This chart displays the
> range when there would be no influence of available light." Knowing
> that a fill flash should provide about 20% of the total light and also
> knowing the guide number at a given shutter speed one can calculate a
> reasonable fill flash exposure... but it will be time to go home before
> I'm done.
The e-sif and my F280 paper manual are a bit different there, but both
provide the chart with the shutter speed curves. That includes both the
aperture and the distance (which, I assume, is the recommended distance
for fill flash in Super FP mode - it smaller than GN/aperture).
Using this chart, I made a crosstable with shutter speeds and apertures.
You can make one such chart for each film speed and it should provide the
necessary information reasonably fast. Even the GN table, which would
indeed be useless in the field, can be used to pre-calculate such tables.
In general, following the pre-calculated tables for distance, I've found
that the flash has been roughly 1 stop weaker than advertised. Maybe I'm a
bad judge of distance. The +/- dial should work for compensating for the
background. As for controlling the fill balance, the only way I can think
of is getting closer or backing up.
Priit.
--
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