: 1080p or 1080i

2007-12-21, 08:15 PM
I have a year old Sony 40" LCD which I may soon be passing to my son. Re- my next purchase I would appreciate answers to 2 questions as not sure I can rely on salesmen
1. I know 4:3 SD is not great on a widescreen HDTV, and my present tv is testament to that. Would SD picture quality on a 1080p tv be expected to be inferior to SD on a 1080i tv due to more pixels on the screen?
2. Would one typically expect SD on a LCD tv to be a bit inforior to that on a plasma or can it go either way.

2007-12-21, 08:24 PM
1. I would say it won't make any difference for SD, likely not much difference for HD either (especially on a screen size < 50").

2. It could go either way but generally, the bigger the television, the worse the SD looks. If SD is what you're mainly watching, I'd stay with a smaller screen size (less than or equal 40").


2007-12-21, 09:46 PM
TVs are cheap these days. Get a $500 32" 720p for legacy viewing and a 58-60" 1080p for HD.

2007-12-21, 11:28 PM
It would depend on the TV, however, SD PQ can depend even more on the proper setup of the STB and the TV. The following post provides additional information on that topic.


There are some TVs that provide better PQ with SD signals, but it's very difficult to say one is better than the other without discussing very specific models. One can certainly not generalize regarding Plasma/LCD.

2007-12-22, 02:08 AM
I'd have to disagree with the comment that the bigger you go the worse the SD looks. It all depends on the TV. SD on my 50" Panasonic plasma looks way better then on my 37" Sharp LCD.

2007-12-22, 10:02 AM
Thanks for these replies. Some suggested to be more specific so based on my previous evaluations, at the outset I'm probably already restricting myself to plasma being Panasonic and LCD being Sony/Sharp/Samsung. Probably also thinking 42" if plasma and 46" if LCD.

2007-12-22, 01:53 PM
SD on my LCD is pretty darned good. There's the odd analogue station that's terrible, but then again they're bad on my CRT as well. I don't think you'll go wrong with either of your possible choices.

2007-12-22, 03:15 PM
..... Would SD picture quality on a 1080p tv be expected to be inferior to SD on a 1080i tv due to more pixels on the screen? .....
There is a fundamental misunderstanding here. An HD TV display will be either 720P, 768P or 1080P native resolution. There are no 1080i HD displays (to my knowledge) other than older CRT rear projection units. The broadcast input signal will be 480i for SD and either 720P or 1080i for HD. The TV will map the input to the native resolution. Some may do a better job than others in the upconversion and/or deinterlacing.

There are numerous posts discussing tests showing models that do not de-interlace the 1080i input properly, in effect only using half the input signal. Do a search to find those as they will explain the de-interlace process and hi-lite models (not brands) to be avoided.

2007-12-22, 04:06 PM
Here are the links to the two subjects discussed by COTU.