Build Nipkow Lens disk

[rld-tv01]

I was thinking about building a lens disk mechanical camera and monitor. I have an old mechanical TV camera/monitor kit from Peter Yanczer which I would use for the mechanical drive mechanisms. I've been perusing the internet for ideas on building the lens disk. I found the following on the NBTV site.
http://www.taswegian.com/NBTV/forum/...it=+lens+disk+

I then found the following on eBay
http://www.ebay.com/itm/321551480274...%3AMEBIDX%3AIT

I like the idea of sandwitching two disks with the optical beads between the layers to keep the beads from flying off and killing someone. Would the eBay lens above work? Anyone know where to buy inexpensive optical beads suitabile for nipkow disk. What size holes and lens would be best for the disk?

[earlyfilm]

Originally Posted by rld-tv01

I was thinking about building a lens disk mechanical camera and monitor. . . . . . . I like the idea of sandwitching two disks with the optical beads between the layers to keep the beads from flying off and killing someone.

Just wondering why you chose the rather large 13mm size?

That will force you to make a the wheel larger than it otherwise would have been.

Unless you make the wheel huge, I don't see why mounting a light plastic lens would be any less safe than a CBS color wheel.

The CBS wheel (with 6 sectors) ran 1440 rpm, in the 24 fps 6 interlace system.

At 15 fps per second, a Nipkow disc will only turn 900 rpm, and half that if it were interlaced with two spirals that were offset by one-half line width.

James

[rld-tv01]

I haven't purchased any lenses yet. I've been looking on eBay and http://www.surplusshed.com/lens.cfm Cost is a major concern. Surplus shed has better specs on the lens but they are $3.50 apiece with a minimum of 10 lens. Multiply by 45 lens then more then I originally wanted to spend. The ones on eBay are under $15 for 50 lens but nothing stated about focal length just the size of the lens.

From the ETF site http://www.earlytelevision.org/weste...storation.html
"The scanning disc used with the new motor was aluminum and about 8 inches in diameter. Forty five lenses about I cm. in diameter and having a focal-length of 1 inch were arranged in three interlaced spirals. It was important that the optical centers of the lenses be accurately located to provide a uniform scanning field without dark lines."