Several episodes of the classic British comedy series “Dad’s Army” were thought to have been lost, due to the original videotape being wiped for re-use, some 40 years back. Then someone recently found black and white copies on 16mm film. Better than nothing, but of course colour infomation gone for ever – or so you would think.
Normally these patterns are small enough not to be visible.
Now the black and white copies of the Dad’s Army episodes were made, rather crudely, by pointing a film camera at a high quality (colour) TV screen, and shooting (in black and white). And guess what – the quality of the camera was high enough to record the individual dots. So by looking at the relative brightness of each dot in a group of three, we can deduce the colour information at that point. Absolutely delicious use of technology!
Actually, the recording was made (effectively) by pointing a film camera at a high quality *black and white* TV screen, not a colour screen as you describe. Therefore the explanation you give for how the process works is rather wide of the mark!
