Chuck,
I have a 60 CT-4 which is similar conceptually, but not completely the
same. I believe the 45 CT-5 is an SCA-500 series (for OM's it would use an
SCA-520). Metz makes (or at least made) a couple adapters to allow
interchanging SCA-300 stuff with SCA-500 but I've never used or seen them
so I only know they exist. Otherwise, as I understand it, it's much like a
45 CT-4 in features. BTW, the current 45 CL-4 is identical to a CT-4
except it uses LED's on the back instead of the older style lamps (neon?).
The other pair of Metz units are a 40 MZ-2 and 40 MZ-3i, both of which are
"shoe" mount although with a G-15 or G-16 grip they can be converted into
handle-mount potato mashers. They also have secondaries, and like the 45
and 60 handles with secondary flash tubes, the auto sensor hole is next to
the secondary under the main head. The flash quench, be it TTL using a
dedicated SCA module, or in Auto using the built-in sensor, operates on
both the primary and secondary flash tubes. This is what is puzzling me.
I've never had a problem with the auto sensor built into the head, either
with or without the secondary turned on. That said, there are a number of
methods that can be used to mess it up (and the exposure). In Auto Mode,
the sensor needs an unimpeded view. Block it with anything, even
partially, and you'll over-expose. This includes soft-boxes that *don't*
leak light out the bottom side, but extend too far below the main
head. From your description of his symptoms, one of the possible root
causes is something blocking the view of the sensor. If he's mounting the
handle on a bracket, ensure something on the bracket isn't blocking its
view, even partially.
I played with my 60 CT-4 briefly which has a thumbwheel on the back of the
handle for setting mode and aperture in Auto mode; it also displays max
working range (in Auto mode). There's a knob on the handle's right side
for setting film speed. The dials on top of the head are the calculators
and power reduction settings for use in Manual mode. The settings are
shown with through back-lit cylinders that turn with the thumbwheel and
knob. A slide switch turns the secondary on/off. None of the displayed
settings or controls shift or change when the secondary is turned on, nor
do they shift or change if the main head is tilted or turned. The working
distance is bogus if the head is tilted or turned; too much variability in
bounce conditions to try to predict it. During design of the unit, it was
likely too complex mechanically to turn it off or cover it somehow, so it
remains backlit. The dials on top of the head and working distance shown
on the handle back do change if the built-in super-wide-angle diffuser is
pulled out and flipped up to cover the main head (it slides out from under
the main head). I still marvel at the simplicity of the mechanical linkage
that does this. Don't know if any of the 45 series handles have this
diffusion panel or not.
Pulled out the 40 MZ-2 and played with it. Unlike the mechanical rotating
switch controls on the 60 CT-4, nearly all its controls are completely
electronic including an LCD panel display on the back. With the flash in
Auto mode, the working distance changes when the secondary flash is toggled
on/off, and that's it. If the main is tilted upward or turned, working
distance is not displayed. It would be bogus if it were, and with an
electonic LCD panel, it was undoubtedly a simple logic task to do that.
FYI (under-exposure problems):
Softbox leakage, if it falls on the sensor can result in serious
under-exposure. The Sto-Fen Omnibounce type devices that protrude from the
front of the main head must be used very cautiously. With the Sto-Fen, the
head must be tilted upward to at least the first increment of tilt. Light
scattered by diffusion through the bottom part of the box *will* get into
the auto sensor. I was fortunate to discover this by experimentation
playing with a Sto-Fen when I bought it for the 40 MZ-3i. (In TTL mode, it
doesn't matter.) Bounce cards, and Metz makes some good ones, are my
recommendation if you're going to use the flash in Auto mode.
One last thought comes to mind. These flashes are anything but low
power. There *is* a minimum working distance and that is driven by film
speed, the aperture setting (on lens in TTL and on flash and lens in Auto),
and minimum flash duration (the limit to how fast it can quench). If
you're using a wider aperture and move in too close, you will get
over-exposure from the inability of the flash to quench faster. In my
experience it doesn't happen often, but it can, and the risk of it is
higher with powerful flash units.
Don't know if this will help or not. I'd be looking first at something
blocking or reducing reflected light reaching the sensor. This is the
usual culprit.
-- John Lind
At 05:23 PM 6/26/04, Chuck Norcutt asked:
>A friend just purchased this flash on the bay hoping to use it in normal
>auto mode. He was attracted by the swivel/bounce main flash and the
>small fill flash unit with auto sensor on the front.
>
>Seemed like a good thing but testing it he finds that the front facing
>fill flash wants to seriously overexpose the subject... maybe two stops.
> Taming it has required both adding a diffuser at the front (to cut
>output and tame harsh shadow) and lying to the flash about the aperture
>or ISO speed. Since telling the flash lies about the aperture or ISO
>does cause it to quench earlier it appears that the auto circuit is at
>least working somewhat.
>
>I know John Lind is a Metz user but don't know about this particular
>model. Anybody have any experience with this flash that differs from
>this overexposure behavior?
>
>Chuck Norcutt
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|