HDTV resolution confusion
April 23, 2007 6:50 AM   Subscribe

How do HDTV resolutions work, really?

I'm starting to do the research on buying an HDTV for later this year. Plasma/LCD/DLP/next-big-thing debates aside, I'm a little confused about the concept of "native resolution" and "upsampling".

I've seen HDTVs with resolutions of 1024x768, 1366x768, and of course true 1080p (1920x1080) (although my price range is currently below the 1080p level, which is why I'm more concerned).

1024x768 isn't 16x9, so how does that work? Does it look crappy?

Also, none of these have exact multiples of 480 lines, so how exactly does "480p" work (I've got a Wii and a regular DVD player, so this would probably be the most common mode I'd care about)? Does it show up in a smaller 480-line (or 960-line) box? Or does it squish/stretch/distort the picture in some way to fit it into the full screen of lines (in which case, how does that make it much better than an interlaced picture?)?

Or is "native resolution" really something that I don't need to worry about and probably wouldn't notice?

Looking for personal experience as much as technical answers. I hope that's not too chatfiltery :)
posted by jozxyqk to Technology (9 answers total) 8 users marked this as a favorite
This is an important return question to yours: How big of a TV are you buying? 1080p won't mean squat for perception if you are buying about 37" or under. Above that, you may see some additional clarity.

FWIW, I bought a 1080p Westinghouse 42" monitor recently, and the picture is fantastic. *However*, I don't have a 1080p source-- I have cable HDTV, which currently is only piping in at a max 1080i. I also watch DVDs (480p) and they look excellent, though I can absolutely tell the difference in clarity between DVD and 1080i.

Watching sports in 1080i is like having a slightly otherworldly experience...hockey where you can see and follow the puck...golf where you see the slope and grain of a gree...baseball where you can see the texture of the uniform. It's crazy good.

I imagine 1080p might slightly raise the bar over 1080i on a 42" TV, but it's difficult to imagine being more satisfied with the picture.
posted by mcstayinskool at 7:24 AM on April 23, 2007


First, get rid of the 1024x768 choices. Those are 4:3 aspect ratio pretty much like your old tv, old computer monitor, and not at all wide screen which is really what you want to get that cinematic experience on your DVDs and Wii.

posted by zackola at 7:46 AM on April 23, 2007

How big of a TV are you buying?

42 inches seems to be where I'm starting from. It depends on where the $1500-$2000 price point is later in the year...
posted by jozxyqk at 7:48 AM on April 23, 2007

It depends on where the $1500-$2000 price point is later in the year

Considering 42" 720p can be had for $1000 or so with careful shopping, you will certainly be looking at much bigger by the end of the year, even if you want 1080p.

1024x768 isn't necessarily 4:3 aspect ratio, though. It depends on what shape the pixels are. My 42" Philips has a 1024x768 resolution and it's definitely widescreen. It just has rectangular pixels, is all.

To answer your questions, no, it doesn't look crappy. Possibly not quite as good as a panel with true 720p native resolution (1280 x 720), but that's in theory. At normal viewing distances, it is fine.

480p works just the same as any other resolution -- the TV scales it to match the display. All widescreen TVs have various scaling modes so you can choose exactly how it is stretched. What you will do with your DVD player is tell it that you have a 16x9 display, and it will output a 480p anamorphic signal (i.e., a full-height widescreen picture squished into a 480p 4:3 picture) and your TV will stretch it horizontally. This gives you better resolution than having the DVD player do the letterboxing and having the TV blow that up to fit the screen.
posted by kindall at 8:02 AM on April 23, 2007

1024x768 is rectangular when the pixels are rectangular. That's what a plasma of that resolution does.

Every HDTV has a scaler chip in it, as they need the ability to resize content to the screen's native resolution. They have to, as HD can be broadcast in a variety of formats, from 480P to 1080i. The TV has one native resolution, so to fill the screen, everything else has to be scaled to fit.

No, the result isn't squishy or distorted, unless you ask it to be. My TV (720P LCD) has a variety of modes. "1:1" will limit my DVD player's output on the 720x480 pixels in the center of the display. "Aspect" is the right one, where it just automagically scales content to look right. There are other modes that allow 4x3 content to fill the 16x9 area, one that stretches evenly, one that stretches the sides more than the center, making a funhouse mirror effect. I can't see why any sane person would use either of them.

Not all scalers are created equal. I can't tell you which are superior and inferior, but once you start making choices, there's an overwhelming amount of information at avsforum.com
posted by Steve3 at 8:17 AM on April 23, 2007

Funny, I'm just going through this exact buying process. In addition to the good information already posted, in the world of plasmas I haven't found any panels with true 720p resolution (~1365x768) under 50". All of the 42" Plasma TVs that I've found are 1024x768, while there do seem to be some true 720p LCD panels and DLPs seems to run a gamut between those. Additionally, you can get 1080p in a DLP for about 25% less than in any of the flat panels.
posted by rhizome at 9:12 AM on April 23, 2007

I look through a lot of flyers and advertisements for HDTV's, and I think I can say that for the most part, the vendors have NO IDEA what they are talking about. Specs are so often misquoted or mixed up as to be meaningless. Check with the manufacturer if you see something advertised as 1024x768 or 1024x1920, or 760p, or any other random combinations of digits that people like to use to advertise something they don't understand.
posted by blue_beetle at 9:32 AM on April 23, 2007

Another thing to take note of if you are in the market for a 1080P set. Check to make sure that it actually accepts 1080p INPUTS. I was shopping around November/December and I saw a Toshiba that looked really great and it was 1080p and was cheaper than other name brand 1080p. The reason was that it did not truly accept 1080p sources (pretty much the only thing that is true 1080p are blu-ray/hd-dvd/playstation3). Which means that you'll only be able to select 1080i and that the TV is going to scale up to those pixels. So its not really using the native resolution as it should.

I purchased a 42" LCD 720p and it works great with a computer, xbox 360 and cable & air HDTV.
posted by ijoyner at 9:35 AM on April 23, 2007

There seems to be a significant price difference between HD monitors and HD TVs. The difference is that the TVs have built in tuners - which are totally unnecessary if you intend to have a cable box or satellite connection. HDTVs (with tuners) are only necessary if you intend to watch broadcast HDTV (i.e., rabbit ear reception) - which most high end consumers won't be doing. Shop wisely.
posted by grateful at 6:39 PM on April 24, 2007

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