P3D Re: Outdoor shots ok; Flash picture underexposed

[Peter Davis <pd@xxxxxxxxxxxxx>]

At 05:54 PM 1/28/99 -0700, Dr. T wrote:
>I suspect that you are setting the flash wrong or your main subject
>is too far away to be illuminated adequately.
>
>>2) The camera's flash synch is off.
>
>What can happen is for the flash to fire when the shutter is not all
>the way open.  Then you should see darker corners and sometimes
>one side (R or L) darker than the other.  This could be a possibility.

I'm not seeing anything like this.  The flash shots are uniformly underexposed.

>>3) The camera's other settings (shutter speed, aperture) are off. 
>
>I don't think that's the problem.
>
>Tell us more about the flash and how are you setting it.

The flash is a Vivitar SMS 40D "Zoom Thyristor" that I bought used, without
a manual, for $15.  I filed a groove in the foot to fit the Realist hot
shoe.  I don't have any manual, so I don't know what the settings are.  I
shoot Kodachrome 64.  There are 3 interrelated controls I don't fully
understand.  First, at the base (on the detachable camera adaptor part),
there's a multiposition switch whose positions are labeled:

	red dot
	blue dot
	orange dot
	M
	little yellow triangle
	.EM

The lens of the flash can be pulled out or in for wide angle, normal, or
telephoto shooting.  I usually keep it at normal.  This sets a range/depth
guage, which is marked with colored lines.  The lines are red, blue and
orange, presumably to match the dots on the switch beneath.  The lines also
relate to an aperture scale which is shifted left or right by a switch
which selects ASA.

So, if I set the film speed to 64, and the length to 'normal', the orange
line indicates 10 feet at f/5.6, the blue line indicates 20 feet at f/2.8,
and the red line indicates about 40 feet at f/1.4.  I would normally set
the switch at the bottom on the orange dot (10' at f/5.6), and shoot at
1/50 sec.  I have no idea what the little yellow triangle or the .EM
settings are for.  I'm guessing 'M' is manual.

Also, the little yellow triangle matches one on the ASA setting switch,
which is to the left of the normal indicator.  So, if I set the ASA to 64,
the little yellow triangle on that switch points to about ASA 400.

I don't know if any of this is decypherable.  It seemed to me that, without
worrying about flash settings, I was able to get successful flash pictures
on my 3.5, and not on my 2.8.  However, it may be that I've changed some
critical flash setting without realizing it.  Perhaps I should try to find
a copy of the manual for this flash and see if I can figure out what
everything does.

Thanks,

-pd


--------
                                Peter Davis
                Funny stuff at http://world.std.com/~pd/

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