> > Another question then, if the flash sync speed is 1/60 ttl, why does
Carl
> > Shipman in his book say to "set shutter speed to1/30 or slower" when
using
> > manual operation or normal auto operation (page 97, 98, 10th edition)?
Is
> he
> > just trying to be extra careful? Is there some circumstance where they
> don't
> > sync at 1/60 manual and 1/60 mechanical?
> > Wayne
> Wayne ... what I think Shipman is saying by setting the shutter speed to
> 1/30 or slower is to allow for more ambient light to reach the film. >
> John H
Well maybe, but I went back and read it again, and it seems to me he is just
describing how it works. I can't see that he's talking about balancing
ambient and flash in that section. I think he made a mistake. If not a
mistake or typo, then while the theoretical sync speed is 1/60 in manual or
mechanical mode on the 2s, the actual and practical sync speed is 1/30.
On page 92, talking about ttl, he writes, "the theoretical X-sync speed for
OM cameras is 1/60 second but there are practical considerations that
sometimes suggest using 1/30. This applies with a flash on TTL automatic."
He goes on to explain, as we know, that if the ambient light requires a
faster shutter speed, the flash won't fire. So let's say the ambient
requires 1/70, then the flash will not fire. We would be fooled becuase we
saw 1/60 in the finder, thought it would fire, and got fooled because the
viewfinder doesn't display 1/70. So by setting to 1/30, we know it will fire
for sure. Albeit it fires at 1/60, PERIOD, as Tim says. So we need to adjust
until we see 1/30 in the viewfinder, which means if we're in auto mode, we
get an aperture setting for 1/30 ambient light, but it still really fires at
1/60 because that is what the flash tells it to do. (Forget program mode, we
never know for sure what its going to do there) So the ambient is actually
reduced even more than needed by the smaller aperture required to get the
viewfinder reading down to 1/30, while it actually fires at 1/60. Using ttl
then makes it harder to balance ambient and flash, as you'll normally have
to remember you'll be at least one aperture/stop under for ambient.
However, what I asked was, why does he say to set it to 1/30 or slower when
using flash in "normal auto operation" or "manual operation". His
instructions, repeated twice (pgs. 97,98) are "Set the camera to manual.....
Set shutter speed to 1/30 or slower". Going back to his statement above
taken from page 92, I can't see why the thoeretical sync speed applies when
setting the shutter speed manually, as he seems to make it. And if we're not
setting the shutter speed manually, there is no sense of talking
theorietical sync speed anyways, because it fires at 1/60 Period, according
to Tim. The shutter speed isn't actually changed, only the number in the
viewfinder is changed.
Maybe I am more confused, but right now I'm assuming (hoping) he made a
mistake, because I've been using the rule of 1/60 or slower, not 1/30 or
slower, when the camera is set to manual shutter speed.
Wayne (still open to learn if someone can get it through my thick head)
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