The T20 and T32 panels should be set to the side that says "manual" on
it somewere and also the one with the ISO slider on it. The TTL side is
very plain in comparison.
If the T32 is in manual mode it's power output is determined by whether
the power switch is at full power = 32 meters (104 feet) or 1/4 power =
16 meters (52 feet). If it's on one of the auto mode positions the
power switch is set at one of the 3 marks indicated as "normal auto".
These are actually aperture markings whose actual value is controlled by
the ISO slider at the top. When the flash is actually used in auto mode
as it was intended to be you first set the ISO value on the flash for
the film in use. That positions the aperture slider and gives you three
apertures to choose from. You select from one of these apertures and
set that aperture on both the flash and the lens. You make your
aperture choice based on desired depth of field and also on the maximum
range that each aperture allows which can be read off the distance scale
above the aperture scale. The T20 only has one manual power setting (20
meters) and only two aperture choices in auto mode.
For example with the T32: You set the ISO at 100. From that you can
see that acceptable apertures are f/4, f/5.6 and f/8. You opt for
maximum depth of field so you choose f/8. But above f/8 the distance
scale will say about 4-5 meters max distance. (I don't know exactly, I
don't have a metric scale on my T32s). Had you chosen f/4 the maximum
distance would be double that.
Now that you've learned all this you need to mostly forget it because
that's not how you're going to use the flash. All those markings on the
flash assume that you're shooting your kid's birthday party probably
some 2-4 meters away. Instead, from the flash's perspective you're
shooting the backside of a piece of canvas from 1/3** meter. The
precise markings on the flash regarding ISO, aperture and distance will
be meaningless. But that doesn't mean that they're not useful. Those
controls will still control the power output of the flash... it's just
that we don't know the precise amount of light each setting will produce
nor how much of it will get through your improvised diffusers. But we
don't need to when shooting digital. Determine that by experiment.
** I would suggest that you use a minimum distance in auto mode of at
least 1/2 meter if not a full meter. From the flash's standpoint you're
taking a photo of the back of the diffuser material. If the flash is
too close to the diffuser the electronics may not have enough time to
quench the flash before overexposure results. As you may have heard,
light travels extremely fast. If you're shooting with the diffuser 1/3
meter away you're only giving the flash about 2 nanoseconds to measure
and shut off the light. The T32 has a shorter minimum range than the T20.
Set your camera to manual mode and shutter speed at 1/180 second. You
don't "configure" the sync speed, you simply set the shutter speed in
manual mode at less than or equal the maximum sync speed. Set the
aperture on the lens to whatever you think you need for requisite depth
of field.
With the camera in manual mode the camera has absolutely no control over
the flash except to trigger it. With the flash in auto mode the flash
is in complete control over how much light is created based on the
amount reflected back by the subject and measured by the flash.
Note that, in auto mode, changing the flash unit's setting to a small
aperture will cause the flash to increase power since it thinks the
camera is dealing with a small aperture. Changing to a small ISO value
will do the same since the flash thinks the camera is loaded with slow
film. So maximum power output on the T32 in flash auto mode is given by
setting the flash to ISO 25 and aperture all the way to the right at
f/4***. Minimum flash power is given by setting ISO to 1600 and
aperture all the way to the left at f/16***. I would suggest starting
with the flash at maximum power (ISO 25, f/4). If that's too bright
then start increasing the ISO. Go to 50 and take a test shot. Go to
100 and take a test shot. If you get all the way to 1600 and it's still
too bright then start moving the aperture slider to the left. If you
can't find a good brightness level by tweaking the sliders on the flash
then you'll have to do further exposure control using the aperture on
the lens. But don't change the shutter speed. Using a T32 you cannot
change exposure with the shutter. At some point you will find a
pleasing exposure.
*** The use of f/4 for maximum power and f/16 for minimum power may seem
to be a contradiction to what I've just said about how the flash
controls the power output. However, these settings are relative to the
three stop range available at any given ISO setting. At ISO 25, f/4 is
the smallest aperture setting available on the flash. At ISO 1600, f/16
is the largest aperture available on the flash.
For white balance first find the proper exposure with the flash units in
the expected configuration (bright white background and no blown white
bits). The follow the instructions in the E-500 manual as I outlined
before using the same white background.
When you're setting white balance, even though it be reflected back to
the camera you are in effect trying to measure the color temperature of
the incident light. Once you've achieved that you can replace the white
background with anything of your choice. I'm assuming here that the
reflectivity of the background does not contribute significantly to the
exposure. If that's not a good assumption then changing the background
to something darker could require that you increase your exposure slightly.
Chuck Norcutt
On 10/2/2010 6:08 PM, Olaf Greve wrote:
>
> Some questions (I know, I can RTFM most of it, but if you know off-
> hand, that would help):
> 1-What should be the position of the panel on the back of the T20s?
> "Auto OM-2" or manual, setting it to a specific ASA setting? Or
> doesn't it matter when manually setting them off?
> 2-How do I set the camera correctly? Switch on the top goes to 'M',
> but what should the other settings be? i.e. where do I configure the
> flash sync speed to 1/180th, etc.?
> 3-How is the WB set properly? Put the camera in the mode you mentioned
> previously, and then take a picture of a white paper, using the very
> same flash set-up and triggering as during the real pictures, or
> should another trick be performed for that?
>
> Cheers and thanks again,
> Olafo
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