Go Back TV - Video - Vintage Television & Radio Forums > Television Broadcast Theory

We appreciate your help

in keeping this site going.
Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 02-11-2018, 02:38 AM
ppppenguin's Avatar
ppppenguin ppppenguin is offline
VideoKarma Member
Join Date: Oct 2009
Location: London, UK
Posts: 271
As old_tv_nut has said, there are so many other variables in the transmission chain it's almost impossible to compare the relative performance of 720p and 1080i in the home.

Interlace was once a wonderful system to reduce bandwidth but it's now just a curse. It's difficult if not impossible to undo it accurately for progressive displays. All flat panel displays are progressive. The best one can say is that receivers have got better, the days of the 2 field splitting apart to give comb shpaed edges on moving objects have largely gone.

[rant] Another curse is the old USA frame rates of 29.97Hz etc. Except they don't affect the home user, only programme makers/distributors. First introduced to cope with NTSC colour (they either had to move the sound subcarrier or frame/line rate to make it work OK) it was a valid choice at the time. That was before timecode. It's been a total PITA ever since, as timecode has to be frigged to make it work with these frame rates. (I'm in a 50Hz country where everything works just fine - I just happen to design kit that has to cope with all standards in the studio.

When HD came in why on earth were the 29.97 etc standards retained? If you needed to re-use old material in a true 30Hz/60Hz standard environment you just played it in 0.1% fast. The madness has been retained in the 4K era, where the SMPTE standards documents still allow for these wretched frame rates. [/rant]
Jeffrey Borinsky
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 06:09 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
©Copyright 2012, All rights reserved.