Hi. I'm new to the forum. I am very curious as to how Baird's 30-line system worked. I've read several articles about it which are often accompanied by photos of him with a scanner that has what looks like a cardboard disc with sixteen holes with lenses. The holes are arranged in two identical spirals so that each spiral has eight holes and takes up half the disc. Also, any two holes that are opposite each other appear to be the same distance in from the edge of the disc so they would be scanning the same area. If this was indeed the scanner for the 30-line system, I can't see how he was able to get a thirty-line picture when there were only eight hole positions.
Can anybody explain to me how it worked or suggest any books or websites that explain it properly? There are also two other discs as part of the system but I've never been able to find out what they are for. I've seen a lot of discussion about 32-line pictures so does this mean that Baird's system somehow got four lines from each hole and that his system really was a 32-line, not a 30-line system?
Many thanks.