Glenn's Junk Chest

An assortment of Glenn's writings, photography, gaming resources, flash movies, and other creative output.

Thursday, January 04, 2007

20 Good Things: 3 - Samsung 46" Widescreen Slim DLP HDTV

Specifically, the HL-S4676S model.

As many of you probably already known, We recently took the plunge and decided to purchase an HDTV. Knowing what I knew about video, I had some specific expectations going into the experience, some of which were validated, others of which... weren't. If you're interested in the ins-and-outs of the current state of HDTV, read on. If not, I'll simply say that the model I name above is a very very good compromise on all of the possible pros and cons.

For those who want to know more, here's the skinny. HDTV is the new standard broadcast model. In the next few years, all of the existing NTSC broadcasts will cease, and people with old sets (who don't have cable or satellite or whatnot) will need to buy a new tuner in order to continue to receive broadcast television. The old broadcast standard employs a system of sending images that works like this: Every 60th of a second, one half of the image is sent as a series of horiztonal lines. On the odd 60ths, the odd lines of the image are sent, and on the even 60ths, the even lines are sent, to be slotted into the empty spaces between the odd lines. This alternating between even and odd lines is called "interlacing". The end result is an image with an effective resolution of about 720x480, and an effective framerate of about 30fps. Toward the end of the SDTV (Standard Definition TV) era, certain sets have become capable of dealing with images that weren't interlaced but rather were "progressive" with all the lines coming in a batch that started at the top and worked down to the bottom. When you see a "progressive scan dvd player" it means it is capable of outputing in that new format.

HDTV starts with this and goes up, but they give everything names:
480i - 720x480 30fps interlaced video, as above.
480p - 720x480 30fps progressive video, like what a progressive scan dvd player can output.
720p - 1280x720 30fps progressive video.
1080i - 1920x1080 30fps interlaced video.
1080p* - 1920x1080 30fps progressive video. (The grail of this quest)

(*1080p is not part of the upcoming broadcast standard, and sets aren't required to display it, but it obviously represents the best possible display in this space.)

But of course the format of the data is only part of the equation here. While the HDTV specification has slowly crept into more and more sets, other market forces conspire to add confusion. Heres the high-level list:

1) Video hardware - There's DLP (and many other variants on rear-projection), CRT (glass tubes), LCD (like a laptop screen), Plasma, and finally there's front-projectors of at least two kinds.

2) Gaming consoles - The Nintendo Wii will only do 480p, the Xbox360 renders many things at a maximum of 720p, but outputs them at 1080i through upsampling. The PS3 handles certain video improperly on 1080i-only sets.

3) Inputs - There are four ways to get HDTV-resolution content into a set. Component, DVI, broadcast, and HDMI connectors. There are also legacy needs for s-video and composite video. Finally, audio signals come in two channel and multi-channel formats, and some of those are digital formats while other are analog formats.

4) Most broadcast channels (in Madison, at least) are at 1080i, but some are at 720p, and some legacy content is at 480p or even 480i.

5) Older PVRs (like Tivo) work at 480i.

6) DVDs are usually encoded at 480p, but non-progressive DVD players can only work at 480i.

7) The screen is a different shape. Old TV was 4:3 (4 units wide by 3 units high), but HDTVs are all 16:9. New DVDs are encoded with this aspect in mind (16x9 enhanced) but old DVDs especially from 20th century fox and Disney, often weren't. Broadcast TV is an almost indecipherable mashup of widescreen, non-widescreen, 16x9 and 4x3 content. Even DVDs that encoded properly for 16:9 sets often have 4x3 content for the extras.

8) Cable and satellite services you already have are probably 480i. You may be able to get a lot of that content in HD instead, but you'll probably need to pay more per month, and you'll need new equipment up front.

9) If you're going to be dealing with a mix of input resolutions (and judging by issues 8, 6, 5, 4 and 2 we are going to have to) it's important to consider which resolutions the set can display natively, and how it deals with content that it can't display except by scaling it.


So, with all this to consider, how did I decide to get the Samsung?

Having decided to purchase a set, I decided to concentrate my initial attention on the first issue, which kind of TV technology to invest in.

...To be continued...


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