This is topic Glass slide projector project in forum Film-Yak at Film-Tech Forum ARCHIVE.
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Posted by William Hooper (Member # 71) on 09-10-2002, 02:05 AM:
This is sort of like Sam Hunter's project.I'm starting to be able to look towards opening, & putting up some front. I wanted at first to just throw a gobo onto the main curtain from the projection booth, but I think what I want is to make a projector which will also show old-fashioned theatre glass slides.
So it looks like a project to re-invent the Brenograph, hopefully from inexpensive materials. That design of separate components, open frame on rails is a great design for adjustment, flexibility, & starting basic with ease of later adding other features.
What would be a good light source for throwing those 4" x 3" slides about 140' to 150' to form an image about 20' high? And what would be the projection lens spec? Where would it be likely to find one?
What happened to Brenkert? Does some company have the mechanical drawings of Brenograph components somewhere? It would make fabrication of the slide carrier simpler.
Posted by Scott Norwood (Member # 30) on 09-10-2002, 06:26 AM:
Do you absolutely need to use the original slides? It might be cheaper and easier (but not as much fun) to rephotograph them and use a pair of standard 35mm slide projectors (hopefully with xenon lamps)....
Posted by William Hooper (Member # 71) on 09-10-2002, 07:08 AM:
The original slides aren't really essential, but the design of the Brenograph & Brenograph Jr. effects projectors would adapt not only to slides, but to gobos (which was the original idea & still desired), effects wheels (which could be scaled up from modern effects projectors).Maybe instead of a gobo, maybe a b&w slide?
That's still a lot of light, & a lot of slide projector lens for 145'!
Posted by Gerard S. Cohen (Member # 994) on 09-10-2002, 08:49 PM:
Wouldn't it be easier to just buy an old lantern slide projector?
They are usually sold with their original sheet metal coffin-like portable cases, with webstrap on top, often with a collection of instructional glass slides. At camera shows and image swap-meets you can still buy some of the old intermission and coming attraction slides that used to be circulated by rental to theatres, though they are increasingly rare and pricey. (Blackhawk of Davenport Iowa sold sets of intermission "policy" type slides reprinted on 35mm 2" slides.) These old monsters, some with blowers, exist in great numbers and there is almost no demand for them. They had names like Balopticon, Stereo-Opticon, etc and often featured optics by Bausch & Laumb, but were manufactured by many prominent factories. I worked with a professor at Brooklyn College once, who used to teach future teachers to make their own glass lantern slides from kits sold in red steel boxes containing all necessary supplies and instructions.
Posted by William Hooper (Member # 71) on 09-11-2002, 12:48 AM:
I thought about a lantern slide projector from eBay, but still would need to hotrod the lens & lamp, leaving only the slide carrier as the used part! Maybe I can pull apart a Leko & mount the bits on rails to get sufficient adjustment (like the Brenograph did!)