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Unusual 3d Concept/ Light for Viewer
- From: P3D <JValaVIDI@xxxxxxx>
- Subject: Unusual 3d Concept/ Light for Viewer
- Date: Wed, 1 May 1996 23:04:16 -0400
>I'm still working on my 2 1/4 stereo viewer and have not found the perfect
>light source and translucent material for it. I tried 6 volt halogens, but
>their too dim. If I switch to 120v source, I'd have to use a large dimmer to
>control intensity instead of just a potentiometer. Thinner translucent
>material gives me hot spots around the bulbs.
I don't know any of the details regarding your viewer design or if you are
interested in "productizing" it, but I would recommend you use fluorescent
lamps to backlight your film elements. In my "day job", doing Optical
Engineering, I have had a lot of opportunity to work with fluorescent lamps
and I can tell you there are many many benefits to using then in this type of
application. Your first hurdle will be where to find them and the power
supply to drive them. But for a prototype or proof of concept model, you do
not need to go any further than your local sporting goods store. They will
have fluorescent camping lanterns there which run off of a 6 volt battery.
If you are industrious enough, you will simply need to remove the little
electronic ballast (power supply) from the insides of the lantern and
re-arrange the lamps and their sockets into your viewer. Light uniformity
shouldn't be too much of a problem since there are many techniques employed
to reflect or diffuse the output of a lamp like this. You could use either
direct illumination to the film with a diffuser between the lamp and the
film, or you might try placing the lamp in a trough type diffuse reflector
painted with Ultra Bright White spray paint. These lamps put out a
considerable amount of light (in such a confined area) so you should not have
too much trouble with the efficiency of your reflector/diffuser design.
Additionally, this light source will run much cooler and more efficient for
the same amount of light from an incandescent lamp. I have a 4" lamp here
that I ran off of 4 AA Alkaline batteries for over 9 hour continuously before
the lamp extinguished. You would probably need 4 car batteries :-) if you
were to try this with a halogen lamp producing the same amount of visible
light (and a fan to cool it).
E-mail me directly if you would like any more information on this an
sources for any size custom made lamp. The lamp ballast is also a crucial
part of this type of light source since the lamps actually operate at 100 -
200 Volts AC. I also have sources for those if any one is interested. I
always thought Dr. George should add a fluorescent lamp upgrade kit to his
viewer modification options but figured he's got enough going on in his life
at this time, he doesn't need to figure out how to incorporate this into a
system.
John Vala
Virtual Imaging Devices, Inc.
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