Probably quite simple to anyone who knows. If High Definition is so much better than ordinary TV why isn't everything in High Definition? Why bother to make the other kind when I am going to turn to it every time?
It is probably not even noticeable. It is like the soap powder adverts that have been improving on their whiteness every year or so for forty years meaning the original stuff must have made things grey. Same with dishwasher tablets. The improved versions have happened so often that the original sort would have been rubbish if they are to be believed.
Does that mean it is not true then, stargazer, and I have been labouring under a misapprehension? My tv is 48 inch, I must admit and so I may be getting more than I think!
HD is better - especially on sets over about 37-40 inches.
If you can't see the difference on a big TV then I suspect you are not feeding your set a proper HD source. You need either a freeview HD signal on channels 50-55 (via a built in HD tuner in your TV or an external freeview tuner via an HDMI lead), or a Sky HD channel signal via HDMI, or a Blu-Ray player again via HDMI.
I despair of the number of people who tell me that "HD is no better" and it turns out that they are connecting their Sky box via a Scart lead, or don't even actually have an HD tuner of any sort ...
And to answer Starby's original question - most new TV programmes are originated in HD - they are then scaled down for broadcasting on SD channels.
It costs more to broadcast HD (more bandwidth needed) and so not all channels will use it (yet) - especially since they will need to continue SD broadcasts too for non-HD receivers.
If you're asking why, for example, there's BBC1 and BBC One HD, it's partly because BBC One HD can't currently accommodate local variations (such as local news).
Additionally, most flat screen manufacturers recommend that, after about 200 hours of use, one either foollow fairly involved directions or, better yet, hires a technician to come 'round and performa abit of electronic magic they call balancing. It made a world odifference in our new 55 inch Plasma model. Especially in the trueness of the colors... Cost about $150 here in the U.S.
Looks as if I shall have to a bit more investigating - that is ask my son-in-law if I have what Dave says. I think I may have because I have only had this tv for a couple of months so it may have something built in. I was really wiondering why they were carrying on doing the ordinary one as well as the HD one, but that has been answered very well. Thanks to everyone.
Maybe just me, but it seems that programmes which have been recorded in HD appear sharper on my old CRT TV than those that are recorded in SD.
And Starry, with the huge number of repeats of old programmes on TV these days, most of what's broadcast isn't in HD anyway!