At 00:00 1/7/01, William Sommerwerck wrote:
Oh, yes... The F280's "cutoff" voltage is too close to 5V to work well
with NiCd cells. If you get ten flashes out of a charge, you're lucky. (I
haven't
tried it with NiMH cells, but I assume you'd have a similar problem.)
I used two sets of NiMH cells in a pair of T-32's for the November wedding
shoot . . . 300 shots, about 950f which were flash. I don't even know
whether the first set would have made it completely through as I changed
them out between wedding and reception. The reception consumed about 200
shots, all flash. The flash recharge time was noticeably shorter than for
alkalines and neither of the T-32's shows any worse for wear from it.
Supposedly, the NiMH cells hold voltage until the bitter end. This is a
boon, but also a problem in charging them, because it is hard to detect
using voltage when they have fully charged. The more sophisticated
chargers monitor several things while charging them to detect when to shut
off. You might have better luck using NiMH in the F280.
IMHO, the biggest risk to a T-32 (or T-20) is repeated full discharge
firing on something like the BG-2 that has a very short flash recharge
cycle, even though the BG-2 recharges the flash using high voltage through
the 3-pin connector. If the flash is able to recharge fast enough, this
can overheat the Xenon tube. Repeated means not just a few in rapid
succession, but a bunch. Its hard for me to imagine a situation in which
one would shoot enough frames fast enough to do this, even at a high rate
of film burn like a wedding. I'm not certain if using the filters over the
front of a T-32 will affect this. A higher level strobe discharge is
required with a filter (or diffuser) over the front of the strobe, and
logic tells me it would also inhibit heat dissipation to some degree. How
much, and whether this is a real or imagined risk would require some
testing to actually measure heat buildup.
One of the advantages of using a more powerful flash setup is that you
rarely have a full strobe discharge. Yes, it shortens recharge time, but
it also does not generate as much heat per flash.
What usually "kills" a T-20 or T-32 is dropping it on a hard surface (e.g.
concrete, or asphaltic concrete), which can do in just about any piece of
OM hardware. Bashing it on-camera and destroying its shoe can, but AFIK
quite a few have been resurrected with a shoe replacement if nothing else
is seriously damaged.
-- John
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