Daniel J. Mitchell wrote:
<< One thing that I
didn't know is that it says that the shutter blinds always go at 1/60th, it
just moves the second one very soon after the first one starts, so that
there's only a small slit of film exposed at any time (1/4 of the film if
it's at 1/240th, etc).
Fair enough, I see how this will guarantee that any given bit of film will
only see the light for the correct amount of time -- but what I don't
understand is how it'll let me take action photos? >>
Don't worry, this is true for most SLR cameras which have focal plane
shutters, and true for all the OMs! This is how you get the high shutter
speeds. I always thought that it must distort the picture a bit, having one
side exposed later than the other, but I suppose it doesn't matter much,
except for _very_ fast-moving objects.
Usually the fastest speed where the film is all exposed at the same moment
(ie the shutter is fully open) is the flash synchronisation speed, which for
most Olympus OM cameras is 1/60 but can be 1/125 or 1/250 for someother makes
of SLR camera, usually those with vertically travelling shutter blinds (they
have less distance to travel) and are often made if metal, sometimes titanium.
That is logical since when the flash fires, and this is more or less
instantaneous (can be 1/40000 - 1/1000 second), the whole film MUST be
uncovered or you don't get a proper picture!
Dave Bellamy.
http://members.aol.com/synthchap/
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