Date: Thu, 17 Jun 1999 12:32:43 EDT
From: WKato@xxxxxxx
Subject: [OM] OM4T fill flash was To OM or not to OM
>I still keep thinking about the fill-flash quandry and want to throw out a
>possible solution.
>The F280 has a maximum range dependent on the F stop. So if you either
>position yourself beyond this range or stop down the aperture enough so that
>the F280 poops out (aiming for a 1 stop underexposure for fill-flash), will
>the OM4 give correct exposure to the background by adjusting the shutter
>speed? As someone posted earlier, the OM77 will automatically go from FX
>sync to X sync at 1/60 but the OM4T will not. Will the OM4T just keep
>reducing the shutter speed to give correct exposure to the background?
>For example with ISO 100 film at f/5.6 the maximum flash distance is 2.5
>m.with the chart showing 1/60 second shutter speed on the F280 Working
>Distance Guide. Now if I stop down to f/8, the flash will underexpose 1 stop
>but will the OM4 decrease the shutter speed to 1/30 to compensate?
>Will this work at higher shutter speed? I don't think so because the OM4
will
>reduce the shutter speed to compensate.
>BTW, someone just offered me an F280 so I will be able to put all my
>speculations to a test.
>Warren
>----------------
According to Olympus Vision Age #6
Full synchro Flash F280 'important feature is its ability to provide full
sync with the OM4t at all shutters speeds up to the super fast 1/2000."
The article then explains conventional ttl Fsync flash then goes on to say:
"The full Synchro Flash F280 is able to maintain its flash duration for as
long as 40 milliseconds........ The exposure is determined by the OM4t OTF
metering system reading the subject brightness and the camera computer
selecting the appropriate shutter speed...."
Now according to my calculations 1/60th of a second is 16.7 milliseconds and
1/30th of a second is 33.3 milliseconds both of which will allow the F280 to
sync in either TTL or FP mode. So, I guess, you can freeze action or blur
action in this shutter speed range on 4t only.
This still doesnt answer some of the other questions about the F280 but I
will try and dig deeper....
Cheers
Ken M
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