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From: alanr@rd.bbc.co.uk (Alan Roberts)
Subject: Re: Film Media to Television Format Conversion
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Date: Mon, 15 May 1995 11:39:44 GMT
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Gareth Rowlands (gareth@lightfox.demon.co.uk) wrote:
:           alanr@rd.bbc.co.uk (Alan Roberts) wrote:

: > in one of two ways: "twin-lens" tks focus the light through a second lens
: > further down the film, "jump-scan" tks move the raster further down the 
: > CRT.

: I fell asleep during the Bob Carr lectures too ....  But tell me, what has happened
: to ye good olde polygonal prism ??

: Cheers,
:  
: Gareth.
 
Polygons allow the film to be run at any speed, but are much more expensive.
The film moves at constant speed and the scanning is done via a polygonal
prism to track the motion difference between the film and the electronic
scanner.

They are somewhat difficult to set up and tend to produce a rather smeared
output, since there's a constant cross-fading between adjacent film frames.
So although it will run the film at any speed, the pictures don't look
very good. 

--
************* Alan Roberts **************
* BBC Research & Development Department *
* My views, not necessarily Auntie's    *
*    but they might be, you never know. *
*****************************************
