Archived posting to the Leica Users Group, 2002/10/31

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Subject: [Leica] Need help with SF-20
From: "Jim Laurel" <jplaurel@nwlink.com>
Date: Thu, 31 Oct 2002 23:34:28 -0800
References: <A47E5AFE-EC59-11D6-94B4-000393AC0E1A@johnbrownlow.com> <3DC21D95.50702@webshuttle.ch>

My SF-20 manual is lost, and I have to leave for Africa in a couple of days,
so I wonder if any SF-20 experts could offer some advice.  I just got back a
test roll and everything shot with the SF-20 was overexposed by around 4-5
stops!

My only use for flash is fill at slow shutter speeds.  So, for our test, I
set the SF-20 to TTL mode, then metered ambient light with an M7 at 1/8 sec
at f2.8.  The SF-20 should output enough light for proper exposure at around
f2.8, but that's not what's happening.  When I tested the flash with a
Sekonic L-508, I got readings of almost f16.  If I set the shutter speed at
1/50th, the flash seems to output the right amount of light.  But at slower
shutter speeds, it's putting out way too much.

In "auto" mode, the flash works just fine.  It's a little hot for my tastes,
but dialed down 2 stops, it is about right.

The problem doesn't seem to be the cameras.  I've tried it on both an M6TTL
and M7 with the same results.  At 1/50th, the TTL mode seems to works fine.
At slower speeds, I'm getting extreme overexposure.

It would seem the flash is defective.  Any other opinions?

Thanks for any light you can shed on this problem.

- --Jim Laurel

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In reply to: Message from Johnny Deadman <lists@johnbrownlow.com> ([Leica] A Deadman 360)
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