This ( inverse square law) topic has already been pretty much beaten to death
by others on the list but here are a few more comments in a slightly
different vein.
The T32 is very powerful for its size and angle of coverage. It is actually
the same power as the much larger Handle mount Sunpak 544 (They are both 70J
(W-sec) ). The higher GN of the 544 (140ft) just reflects the narrower angle
of coverage (area.) This means with a suitable focusing system for longer
lens use the T32 will do well against many common handle mount flashes like
the 544. Unfortunately the Zoom focus head adapter for the T32 is not very
efficient so the GN does not go up as much as might be expected from theory
when used (set to 135mm) with a long lens The downside for the T32 versus
the 544 or 555 say is the longer recycle times especially with used cells
since the 544 runs off 6 cells versus 4 for the T32. The 544 is also more
versatile in available vairiable settings. On the other hand the BG2 /T32
combination gives much improved recycle results with a similar size to the
544 since it uses C cells.
Wayne asked about other add on fresnel lens focusing systems for very high
GN's The Best I have seen in handle mount units is the Metz unit which is
quite large but doubles the GN. This means GN's of about 400ft for a lens
coverage of 120mm focal length. Maybe this add on could be kluged to work
with a T45 or even T32 ??
see http://www.metz.de/mecablitz/eng/produkte/zubehoer/Welcome.html and
look under accessories section
Of the commonly available handle mount units (without an added lens ) the
Metz CT60-4 is one of the more powerful since it achieves a GN of around
200ft but with an angle of coverage of a 28mm lens, a big increase over the
most powerful Sunpak Handle mount (622 pro) which is also 200ft but only for
a 35mm coverage. The theoretical GN for the Metz CT60 if it covered 24mm is
only 157ft versus the T45's GN of about 147ft for 24mm coverage. Thus a T45
with a well matched fresnel lens should be only slightly less powerful than
the Metz with it's lens. Get your flashmeter and experiment with some plastic
fresnel lenses!
John Hermanson has previously posted that the T45 is just two T32 circuits
with two flash tubes in a single housing with a single reflector. This means
this handle mount unit is a respectable 140J unit.
One of the simplest options would be to use two T32's as has been suggested
but with two OM clip on zoom heads. This is probably one of the least
expensive ways of achieving reasonable GN's with a light weight OM rig, as
Barry had originally asked. Adding a Quantum Bantam pack would help keep
recycle times short without adding too much weight. You may have to line up
the flashes carefully with the lens axis
An interesting site with trad flash tubes
http://www.graflex.org/flash/meggaflash/
Here are some GN comparisons for flash bulbs:
http://www.dhios.demon.co.uk/Flashbulbs/Bulbs1.htm
and http://www.graflex.org/flash/ge-5.html
Note some units get to GN 600ft+ without lens focussing ! And in a light
weight package but of course no OTF control!
Quantum's excellent site has GN's for their studio flashes.
http://www.qtm.com/
I previously posted more information to the list comparing GN's of T32's
versus a niumber of popular flashes at different angles of coverage. This
should be in the archives.
Regards,
>> Tim Hughes <<
_hi100@xxxxxxx (remove underscore to reply)
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