When you flip the panel to the "full automatic" side and insert it, all it
does is slide the switch to the "Manual" setting to turn off the flashes
regular "Auto" sensor. This lets the camera's exposure circuit control the
output of the flash.
What should happen with a T-flash, Shoe 3, and an OM-2 is this: With film
in the camera and a lens attached, synch set to "X", the camera should not
begin firing the flash until the needle in the finder is at or below "60".
Once the _actual_ shutter speed delivered by the camera drops to 1/60th
second, the flash should fire, in other words. (Remember -- the needle in
the finder is an indicator only, and does not actually control anything.)
Light from the flash reflects off the subject, enters the lens, and is
reflected off the film into the sensors. Once the sensors have accumulated
enough light, the electromagnet is released allowing the second curtain to
begin closing. The back EMF of the electromagnet is used to send a pulse
into the flash, stopping it's output.
If you are too far from the subject for the aperture set on the lens and the
ISO, the sensors will not accumulate enough light even at full output from
the flash and the OM-2 will keep the shutter open in an effort to collect
more light. If this happens, your only recourse is to (a) move closer, (b)
open the aperture, (c) use faster film, and/or any combination of the above.
This assumes everything is working as it should.
To check for proper synch operation, do this: Charge the flash on "Manual"
or "full automatic", off the camera. Prepare the OM-2 (with or without film
and lens) with the shutter released (unwound), manual mode, speed at "60",
synch on "X". Attach the flash to the hot shoe -- it should _not_ fire.
Wind the camera -- again, it should not fire. If the flash fires either
time, there is a problem in the camera's synch circuit.
Now press the shutter release on the camera. The flash should fire and you
should get a blinking "Auto Check" lamp on the back. Visually note the
quantity of light emitted from the flash. If the flash doesn't fire, or if
there is no "Auto Check" signal when the flash fires (i.e., the flash fires
full power), something's wrong with either the body or the flash. (You
might try a different T-flash to isolate the problem, or send both for
service and let the tech sort it out.)
Now set the shutter speed of the camera to "30" and wind it, wait for the
flashes ready light, and fire the camera again. This time, you should see a
noticeable increase in light output from the flash (full power), and no
blinking "Auto Check" lamp.
>
> Thanks for your response. My camera body, I believe, is the OM-2 with
accessory shoe 3. I have seen photos of the other incarnations and I
believe they are clearly designated on the body. Flipping the calculator
panel on the T20 to the TTL mode forces the selector switch to "manual" and
placing the camera on "auto" should render it all set for TTL auto. I hope
I just have a contact problem of sorts, else please advise, if possible.
> Mike G
>
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