🚀 go-pugleaf

>> Pardon my ignorance, but... doesn't this mean that shutter speed is
>> essentially irrelevant for a flash picture taken using an electronic
>> flash?  If so, how does one control the exposure?

>Correct -- shutter speed is irrelevant for pictures taken
>with electronic flash.

True, for purposes of exposure (unless your shutter speed is faster than
1/10,000 :-) ), but the shutter curtain has to be wide open when the flash
goes off.  For faster speeds, the curtain will be a slit moving across
the negative and you will get a perfectly exposed column or row of the
scene.  Usually, the curtain will be wide open at speeds equal or slower
than 1/60 or 1/125, depending on the camera.  The fastest speed usable
with a flash is usually the flash position on the shutter speed dial;
although you can use a slower speed.  You can see the effect if you're willing
to waste a frame; just turn to 1/1000 take a pic with a flash.

Never mind if you have leaf shutters as on many 120 film cameras :
you can use any shutter speed since there is no shutter curtain.