Ask HDBeat: poor analog signals
by Matt Burns 
posted Nov 18th 2005 at 3:12PM
Jake wrote us a note asking us to clarify something in our HDTV Buying Guide: Choosing the right kind. He is wondering what we meant by "Poor non-digital signal" and "O.K. digital signals" when referring to Cons of a LCD/DLP rear-projection. Well Jake, I hope I can clear this up for you.
I am assuming that you have never owned a big screen before so lets start there. Many people (including myself) have never purchased a big screen because picture quality has always outweighed in importance over the screen size. The same thing can be said here as well. The rear-projection DLP/LCD sets you are looking at are big, sometimes very big. That basic cable (non-digital) signal that some people still have produces a lot of noise that is more evident in a larger screen. The 480i (basic cable and satellite) signal was never designed to look pretty on a big widescreen set. That is why HD is so important.
Size is a simply solution Jake but there is more to it. The tube TVs that make cable look, dare I say, good are the only type of displays that can support both interlaced and progressive scan. They can natively support a 480i (cable and satellite) picture. Here is the kicker, most digital displays do not support that same interlaced picture without some work. They take interlaced picture and convert it into a progressive-scan image by artificially producing the extra data. This process creates a lot of digital artifacts making the cable and satellite pictures look "just O.K." Seeing is believing so take a trip down to a local electronics store and ask them to show you the difference. You will see what I mean.
Feel free to drop us a question and we will do our best in answering it for you.
Reader Comments (Page 1 of 1)
NNTPgrip @ Nov 18th 2005 3:48PM
Indeed. Best thing is to look for TVs that don't suffer burn-in so you can watch analog in a 4:3 box with no fear. Look around, and tune the TVs to something analog. Some have better cicuitry than others to upconvert/interpolate etc., and some have noise filters and overlay filters.
It gets really interesting when you watch something on analog cable that is letterboxed, so you use a zoom mode. - like a close up view of the resolution you're not getting via analog.
Jake @ Nov 18th 2005 5:03PM
Wow, a whole post for little-ol'-me?! :-)
Thanks, that does clear it up some. I would assume, based on this post, that "O.K. Digital signal" wasn't really a Con then, it was just to qualify what you wrote about "poor non-digital signals"?
Are RPTV's just simply worse than plasma or LCD when it comes to SD sources for some reason?
Thanks for the attention, fellas!