HDTV Forum

It's all about viewing distance Henry.

720 is designed to handle 3.2 and 1080 handles 2.5 screen heights based on how close you should be able to get without detecting pixels which will also be technology dependent; with LCD front projection it is difficult to see pixel structure at any distance.

What you are talking about is how far away can you get and still resolve delivered resolution. Both formats survive 3 screen heights, 4 is pushing it and at 5 you won't be able to see it. A multiburst pattern at that distance goes from being fine lines to a gray bar as they blend together in your vision.

The only people wasting money on 1080p product are those sitting too far away which is most folks.

Richard wrote:720 is designed to handle 3.2 and 1080 handles 2.5 screen heights

To make the math easier, that equates to diagonal factors of 1.8x and 1.4x, respectively. I never understood why CVD was give in "screen heights" when TVs are measured diagonally. C'mon, don't make me use math to figure this stuff out.

I submit a proposal that from here on, CVD should be given in diagonal factors, not "heights" ... anyone else?

- Miller

I never understood why CVD was give in "screen heights" when TVs are measured diagonally.

Because it remains the same for all aspect ratios. Another quick conversion...

4:3 = 1.33
16:9 = 1.78
? = 2.35 cinemascope

In a constant height system the above would all be at the same viewing distance. Using diagonal you would end up with 3 different viewing positions. Could write a couple of paragraphs about the explanations along with the if's and's and but's...

Most who use your method round off to 2 X the 16:9 diagonal to get a rough feel when working only with measurements. Standing in front of the display you can imagine and count out 3 screen heights easier than 2 widths. Well, at least I can and maybe from habit...

Granted, but 99% of the time (at least on this site) we're talking about a 16:9 display.

- Miller

Right, that's why I used the word "effectively" meaning what you can physically see at a normal viewing distance. Sorry if I didn't make that clear. The point I was trying to make, and the point in the article, is that for the purposes of normal viewing you're probably wasting your money buying a 1080p set that's 50 inches or less. If you want to sit close and count pixels, then that's an entirely different purpose.

Henry

[email protected] wrote:Right, that's why I used the word "effectively" meaning what you can physically see at a normal viewing distance. Sorry if I didn't make that clear. The point I was trying to make, and the point in the article, is that for the purposes of normal viewing you're probably wasting your money buying a 1080p set that's 50 inches or less. If you want to sit close and count pixels, then that's an entirely different purpose.

But you said "it's not a matter of perception". Now you are clearly admiting what I was arguing: That it is a matter of perception. I may have been taking that to the extreme with my "counting pixels" explanation, but my main point is that you must consider the viewers visual acuity and distance when determining whether 1080p is worth it for that person.

As you say, a "normal" person, with "normal" vision may not be able to tell a difference between 720p and 1080p on a 50" display at a distance of 8 feet. But if that person has better vision, they may be able to tell a difference down to 46" or even 42". Likewise, if that person has poor vision, they may not even be able to tell a difference at 57" or even 60". That's the point I'm trying to make. You must consider all three factors (size, viewing distance and visual acuity), not just 1 or 2. And because of that third factor, visual acuity, there is no hard and fast rule that applies to the entire population.

- Miller

Value of 1080p on LCD's is that you can sit closer and resolve more detail, however, if it doesn't look fantastic at 3 mtrs, it won't be that much better at 1.5mtrs........when I look at 1080 close up, the PQ has more detail and vibrancy, but it's not significant IMO.

That said, 1080 res on 32-37inch LCD's should be awesome for a PC monitor....take a 32 for example, most people can fit one of their PC desk and the pixel pitch will be much smaller than at 1366x768.

Sony are releasing both 32 and 37 1080 LCD, hopefully they're both on sale in OZ.....if the 32 has the 16 000:1 dynamic contrast ratio panel, it should be close to perfect for use as a multimedia device, ie, DVD, HDTV, PC games.

miller wrote: As you say, a "normal" person, with "normal" vision may not be able to tell a difference between 720p and 1080p on a 50" display at a distance of 8 feet. But if that person has better vision, they may be able to tell a difference down to 46" or even 42".
- Miller

I'll be forty in a few months, and whilst I don't wear or need glasses, I can see the difference between 3 and 1.5mtrs on a 46inch LCD with 1080p playback.......the difference isn't staggering, but there's no doubt in my mind that it's there...anyway, anyone can test this for themselves at their local HDTV retailer.

In most cases, the 1080p TV also has a higher spec-ed panel...for example, till recently, Samsung had 3 40inch LCD for sale in OZ, one with 768res+8000contrast, another with 1080res+10 000contrast, and another with 1080res+15 000contrast....the last TV was highly praised for HDTV playback.

I don't think that 1080 res is such a problem, more so the cost, especially with the 52inchers.

Having said all that, Panasonic, Samsung and Pioneer 768 plasma still provide better PQ that any 1080LCD by virtue of plasma's superior contrast, colour reproduction and black levels, etc.

With the exception of Samsung LED, all flat panel LCD's are compared against plasma TV's as a PQ reference point, ie, the plasma is still the best in most cases.

DavidJones4 wrote:Having said all that, Panasonic, Samsung and Pioneer 768 plasma still provide better PQ that any 1080LCD by virtue of plasma's superior contrast, colour reproduction and black levels, etc.

Interesting. I actually think the opposite. I've never liked the "look" of plasma, and always preferred LCD for PQ.

I guess that must be subjective as well.

- Miller

I am an early HDTV adopter. 1080p was not available when I purchased my 48" HDTV. I watch from just under 7 feet away. Picture quality is excellent. I would definately not say that I missed 1080p.

I would not pay much extra to go from 1080i to 1080p either. Many people will pay a significant amount for just that one feature. Progressive scan on a PC monitor close to your seating position is a benefit, but PC monitors show static images with text most of the time. TV has always been interlaced and it works very well. Most of the time you don't see any flicker except when the FBI warning is on the screen. Broadcast HDTV is at most 1080i here in the USA. The only time you will see 1080p is with HD movie players, Xbox 360, and PS3.

With that said if I was buying a new HDTV and there was only a small price difference I would buy 1080p. There is a lot of information that indicates 1080p is such a small improvement over 1080i that most people would never notice so it comes down to cost.

Guys you can waste a lot of time arguing about this. Believe me. I had a long discussion on another site with someone who implied anyone buying 1080i was a fool headed for eye problems, headaches, seizures, and his list kept going. I say buy the bext HDTV you can afford and live with it.