21-01-2021, 04:32 PM
This is speculation, but when the relevant people in the GPO, BBC etc saw 120 line demonstrations they knew TV could be made to give real entertainment. Previous 30 line systems were capable of producing a recognisable image but no more. It's not a big extrapolation to say that when the terms of the competition specified >240 lines they were looking to the future. At that resolution the equipment could be improved to give better pictures without a new system. Even more so for 405, though with moving images it only had 202 lines of resolution.
Looking back, 819 was a failed attempt to get the system well ahead of (then) current technology. 720p was a singularly unimpressive attempt at HD, with fewer active lines than 819 and not hugely more than 625. WIth hindsight I'm not sure why it was ever promoted. 1080i or better, 1080p, gave enough headroom for technology to grow into the system.
Looking back, 819 was a failed attempt to get the system well ahead of (then) current technology. 720p was a singularly unimpressive attempt at HD, with fewer active lines than 819 and not hugely more than 625. WIth hindsight I'm not sure why it was ever promoted. 1080i or better, 1080p, gave enough headroom for technology to grow into the system.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
