Don,
TTL will work with the extension cable if you can convince the camera
that the microscope is a lens with the aperture set to A. I bought a
12mm extension tube with contacts and modified it slightly so that it
always shows as being an A lens set to A. You just have to make sure
that the aperture on the camera is set to wide open or you start to over
expose.
Leon
http://www.bluering.org.au
http://www.bluering.org.au/leon
Don Williams wrote:
Hi Leon,
The beam splitter is not to divide the flash beam, but to allow the
flash to enter the normal light path from the microscope's Halogen or
HBO50 light source. I often turn down the internal light, or shut it
off, before using the flash. But this is not necessary at high
magnification when the light is not very bright and the flash is the
main contributor to the exposure. The beam splitter is a piece of glass.
I have considered a 50% surface coated (interference) filter, but they
are damned expensive. The flashes usually have enough punch to make
plain glass usable. If TTL works with the extension cord I won't have a
thing to worry about.
Don W
Leon Altoff wrote:
Hi Don,
If you are going to use a beam splitter to send light out the
objective to light the subject then I would consider getting hold of
an AF360FGZ and modifying it to work. The tube in the 360 is slightly
shorter from memory - it's been a while since I had mine apart that
far. I spliced a second head at the end of about a foot of cable onto
one of my 360's to make a lightweight twin headed macro flash. The
second head can be unplugged and the flash then works as a normal flash.
I would consider using the wireless trigger on the flash as it's one
less cable floating around. Otherwise you will need to use a 5P cable.
Leon
http://www.bluering.org.au
http://www.bluering.org.au/leon
Don Williams wrote:
Hi Leon,
The flash, which is made from a Polaroid unit and a single straight
flash tube about 50mm long, works very well as a flash. But the tube,
which lies across the beam, causes diffraction in the images. In
other words it doesn't work very well in the microscope. I intend to
use a beam splitter and direct light from a standard flash into the
path. I may even be able to use TTL if I can find a connector that
will satisfy the camera. So the problem now becomes -- "How can I
trigger the Vivitar on the table about 24" away from the camera and
what extension lead do I need?" The camera is on the top of a
monocular mount behind the binocular and using one flash to trigger
another would be very dangerous and unstable. I can imagine the
camera up on top of this 'Xmas Tree' with a flash in the shoe.
Something would give very soon. It would get in the way of my head in
any case.
Don
Leon Altoff wrote:
Don,
The flash on the microscope may have too high a voltage for the ist
D. Once it flashes it may be locking up the camera. Try measuring
the voltage or disconnecting the flash flash after each exposure.
You may not want to keep doing this too often in case it permanently
damages the camera.
A solution to this could be using a slave unit on the microscope and
triggering it with the Vivitar flash.
Leon
http://www.bluering.org.au
http://www.bluering.org.au/leon
Don Williams wrote:
Hi all,
I'm still waiting for the replacement camera and am using the one
with the faulty internal flash. It works with an external flash
Vivitar 730 AFPK perfectly ... but.
On the microscope, which has a simple flash device with no
synchronization, or TTL, or anything at all automatic ... the flash
will flash once and then not again. Its not a question of charge
the flash is made to strobe and will go on flashing with a film
camera until the cows come home at 1/2 second intervals.
What am I doing wrong? I haven't spent much time learning -- I've
been using the camera and it works fine with ordinary lighting on
the scopes. In green, M, or any other setting I might like to use.
All I want is for the flash to flash each time the shutter is
opened. The exposure is controlled by other means and the camera is
not expected to think about this.
Don
