Hi Severi!
>Hi!
>
>I have read a couple of FAQs about how a flash unit works in general, but I
>have
>a few questions:
>
>1. Is the actual duration of flash visible to the user? So if I enter the
>Tv
>mode and select 1/60 s shutter speed, how long is the duration of a flash -
>most
>likely less than 1/60? Is it allways constant (how much?) or does it vary
>in
>different conditions?
>
Flash duration for 380EX is 1.4ms or less, according to manual. My guess is
that onboard flash is somewhere in that region. Flash duration depends on
ambient light, f-stop and shutter speed.
Short duration: high ambient light and/or large f-stop and/or slow speed
Long duration: low ambient light and/or small f-stop and/ot high speed.
>2. What is the actual meaning of X-sync. speed? Why would I want to set it
>1/125
>with CF-9?
>
X-sync is maximum shutter speed allowed to obtain proper synchronization of
shutter open/closing and flash bursting, flash burst must happen after
shutter is fully opened and before it starts closing
>3. Is the brightness of the flash constant or does my camera change it in
>different situations? Does the flash compensation affect this?
>
Brightness/intensity of flash is calculated (precalculated) for every
situation and camera metering system sends it to flash unit. Applying flash
compensation changes flash output for desired/set amount of compensation.
>Thanks for answering these quite basic questions,
>
>Severi Salminen
>
If I'm wrong somebody please correct me!
Good light
Grega _____________
http://fenko.8m.com
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