Chuck Norcutt wrote:
> Anybody here ever measure the actual output of a Vivitar 285HV?
> Measuring at exactly 10 feet one gives me f/8 and the other f/9 or guide
> numbers of 80 and 90. Since that's about 1/3 stop difference I figure
> that's probably within the manufacturing tolerances between flashes.
> But they should be measuring f/12 and that's a stop or more difference.
> In other words, only half the power that they're supposed to be
> putting out.
AFAIK all flash output should be measured in a
defined REFLECTIVE location, sort of simulated
indoors situation. The reflections are expected
to add to total illumination.
That explains why flash outdoors seems so grossly
off to the low side.
Then the capacitor(s) need formation once in a
while. That is to go through several load/discharge
circles to put them to full capacity again. I guess
that has taken place with Chuck's tests.
Then the ready lights go on at approx. 70% charge
and that is official, 'allowed' by some DIN (or
similar) normation. And all makers do use this
allowance to 'speed up' recycling times. If used
in some auto mode, with no need to near full
discharge, no one ever notices.
> When I've measured my T-32's and Sunpaks they've always shown to be bit
> optimistic relative to the spec but nothing like 1 stop below what it's
> supposed to be.
Some maker are more true to reality than others.
Olympus always was pretty correct with coverage and
output values, at least with QA and T series flashes.
> So, my question is, has anybody else actually measured a 285HV?
Not yet ... sorry. I should do, I really should.
Andreas
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