Gregg <giverson@xxxxxxxxxxxxx> moved upon the face of the 'Net and spake thusly:
> OK. But assuming both flashes have the same shape, say for a 24mm lens,
> what w sec corresponds roughly to the T 32? Or to put it another way, how
> many w sec does the T 32 produce?
As was said, Watt-seconds is just a more convenient way of expressing
the output energy (in Joules). Output energy should be on the close
order of input energy (some is lost as heat etc.).
If you know the capacitance and voltage of the main capacitor inside
any flash, you should be able to figure out the stored energy.
A Farad (the unit of electrical capacitance) is defined as two stored
charges of one coulomb separated by a potential difference of one
volt. If C=capcitance q=charge, and v=voltage, then the relationship
is c=q/v.
Now for a given flash, we know c and v (they're both written on the
side of the capacitor), and we want to find E, the stored energy.
Volts are defined as joules-per-coulomb, so v=E/q, or E=vq. However
we still don't know q, but we know c=q/v, or q=cv. So we reformulate:
E = v * cv, or
E=v^2 * c.
So, if you have, say, a 1000uF 400V capacitor, your maximum
theoretical stored energy is .001 * 400 * 400, or, 160 watt-seconds.
Acutal energy will be somewhat less, for reasons of safety fudge
factor and inefficiency, but for the purposes of comparing flashes the
above calculation should be not entirely useless.
We'll call the result of E=v^2c "BogoJoules".
Anyone know the specs for the caps in the Txx flashes?
cjb
p.s. I haven't done analog electronic theory for so long I had to look
up the definition of a Farad, so somebody correct me if I'm wrong...
--
| Christopher J. Biggs | EMAIL: chris@xxxxxxxxxxxxxx (PGP and MIME OK) |
| R&D Software Engineer | PHONE: +61 7 3270-4266 FAX: +61 7 3270-4245 |
| Stallion Technologies | Microsoft is not the Answer. |
\ Queensland, AUSTRALIA | Microsoft is the Question. NO is the answer! /
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|