> O.k., your description of the way the T20 works with your camera indicates
> that the T20 flash properly lets the camera know that the flash exposure
was
> correct (or not when "under" lights up).
Ah, so it works that way around.. I thought it worked like this:
1. Flash tells camera it's charged, pin A goes high. I take picture.
Shutter opens.
2. Camera tells flash to start firing, raises pin C.
3. Flash says "okay, I'm firing", pin B goes high.
4. Camera watches light coming in.
5. Camera decides it's had enough light.
6. Camera lowers pin C.
7. Flash stops.
8. Shutter closes.
If the flash had enough oomph, then pin B is still high when pin C is
lowered, so the camera knows that everything was okay. If the flash didn't
have enough power, pin B will fall sometime between 4 and 5 above, so the
camera knows there wasn't enough and can light the 'under' warning.
> Now, initially I was thinking this flash simply doesn't transfer an
> "exposure o.k." signal to the camera, but...
So TTL flash uses the camera to start/stop the flash, but relies on the
flash itself to tell the camera if there was enough light? That seems
peculiar to me; am I misunderstanding things?
> ...for this I don't have any logical explanation! The only thing I can
think
> of, is that perhaps the Miranda flash does not fit as snugly in the flash
> shoe as the T20 does, hence causing the "exposure o.k." contact between
the
> flash and the camera to not be o.k. Still this would not explain why under
> specific conditions it does work and under others not, unless this is mere
> coincidence.
Well, I'll try cleaning the contacts and see what it gets me -- it
certainly doesn't fit as nicely as the T20 does, but it doesn't seem to be
obviously loose, and the pins all look clean to me.
> How often did you try this?
Lots of times.. I also changed the batteries in the flash and tried again,
no change there.
-- dan
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