Moose wrote:
>>For the F280 flash, which does essentially the same thing as the old FP
bulbs. There are 2 extra contacts on the 3 and 4Ti bodies to work with
the F280 in its FP mode.
<<
Again we posted quite a bit about the F280 Super FP mode previously, a few
years back. It is somewhat kludged onto the Om4 to make Ti version. By far the
best description of the flash-camera co-ordination and interface is in the
OM4ti service addendum. One general issue as with regular FP bulbs, is they
have to trigger the flash much earlier than the normal X-sync, since they need
to start the flash before the shutter opens at all, rather than after it is
completely open. That is why it is strange how they allow regular flash to
trigger on X-sync above 1/60, manual.
Since then I actually spent a bit of time looking at the F280 cct design ,
as I was interested in designing some modified super fp flashes. It is a very
strange design combining a custom logic array with a large number of discrete
transistors connected as gates and level shifters. It has some rather difficult
to set up analog flash rate adjusting ccts. It would be designed very
differently today for a number of reasons.
Regards,
Tim Hughes
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