Why the obsession with big screens? Surely you get worse definition? (1 Viewer)

One of the more curious orthodoxies of home theater is that big is automatically better, and those of us with smaller TV sets (i.e. sub-42") are supposedly not really fully paid up members of the club. What can we possibly see on those teeny tiny sets?

Well, a better picture, for a start - assuming my calculations are correct (let it be said in advance that mathematics is not my strongest skill). If we look at pixels per inch, then a 32 inch set with 1366x768 has 49 PPI, whilst 37, 42 and 52 inch sets with 1920x1080 have 60, 52, and 42 PPI.

In other words, the resolution of the screen in PPI rises from 32 to 37 sets and then declines, so that at 52 inches or above, the PPI is actually lower than the supposedly 'not really good enough for HD' 32 inch set (which, to add insult to injury, has a 1366x768 rather than 1920x1080 screen). And a 42 inch set, supposedly the barely acceptable entry point, is only marginally better than a 32 inch and markedly inferior to a 37 inch.

Now I immediately acknowledge that a large screen has a bigger 'wow' factor when you first enter the room, but if you are sitting the recommended distance back from the screen for the given screen size this really shouldn't matter as the retinal image should be more or less the same. But the level of detail in the picture will not be. [I also agree that if you move from screens to projectors, the loss in detail is offset by the huge increase in the picture size, but that is a different story].

So why should we assume that big screens are the only correct route into high definition TV, and those of us with smaller screens are missing on all the extra details and refinements that high def can bring. Surely it's the reverse?

Note I'm not setting this up in a combatitive mood - I'm genuinely curious about this, and if I've got the mathematics wrong, I'm more than happy to be corrected.

I don't have an answer, but I can relate. I love my 36" Sony CRT (sitting about 7 feet away). I once experienced a custom home theater that blew my socks off aurally, but had a 100" projector screen image that was just way too big and not nearly as detailed as my CRT.

Well I know what Dr. Freud would say about this pre-occupation with size but perhaps there is a less clinical explanation as well.

...What? I'm sorry but your argument doesn't make sense. The size of the pixels doesn't determine the level of detail in the image, only the number of pixels. A 1920X1080 image has more detail than a 1366x768 image does (assuming they're the same image), regardless of the size of the screens. A 23" 1080 screen will show the same detail of a 100" 1080 screen.

Large screens are desired for a different aesthetic appeal. Movies are made to be seen on big screens, to pull you into their world, they're often directed with your peripheral vision in mind. If you watch the end of Star Wars the way you're supposed to, rushing through the death star's trench is incredible as it actually effects your sense of motion. That doesn't happen on a TV. I don't like to sit more than 2 screen hights away, that's hard to do on a smaller screen. (I should know, I've only a 42" screen)

Here's the argument, in a nutshell. The object of HD is not to cram in as much detail as possible, but to allow people to use screens that occupy as much of the field of view as possible. The wider the field of view, the more pixels can be resolved-- and beyond a certain point, it starts to look grainy. Thus, 1080i/p.

Big displays allow you to have a big theater. Small displays force you to sit closer to the screen, and many people aren't comfortable sitting two feet away from the display.

Which is what I said - but the density of the image and hence the resolution on current sets peaks at 37 inches. If that means having to sit nearer to the TV to get the optimum experience, then so be it, but it belies the argument that bigger is better. Viewed at from their optimum distances, the display on a 37 inch screen is currently the most detailed.

You canna change the laws of psychophysics.

I have a room in which the layout allows me around 7-8 feet from eyeball to the screen. I could purchase a 37" screen and have a 46 degree field of view. I purchased a 65" and I have a 76 degree field of view. Since I purchased a 1080p set, even at 7 feet I can't make out the individual pixel elements, so the extra resolution is a benefit, whereas it would be wasted on the 37" at the same distance. So simply stated, I can optimize my room layout without sacrificing the immersive experience.

Huh? What do you mean "the density of the image and hence the resolution on current sets peaks at 37 inches?" The density of the pixels is exactly the same if both sets are 1080p. How exactly is a 37" 1080p screen any more "optimum" than a 65" 1080p screen when viewed from their respective optimum distances?

PS - Andrew, this isn't another "bash the US and their consumption" threads, is it. Because if it is, I'll bow out now. :rolleyes

It depends upon what criteria you are trying to apply to the viewing experience. Larger screens are more immersive and offer a different experience. On a 37" screen your eyes do not have to "wander" and your field of vision is fairly static. On a larger screen you are looking at different areas of the screen at any time and I believe this more closely mimes how we perceive our environment in the real world. Personally, I find larger screens more involving. But that's just my opinion (based on a 720p Front Projector with HD sources on a 106" diagonal screen.)

- Walter.

No - the '1080' refers to the number of lines and the 'p' to the fact it's a progressive scan. It says nothing about the number of pixels in each line. Hence the pixels per inch measure. Suppose you had a fence 100 yards long. You could have fence posts every yard or every 10 yards - the fence would be the same length, but the density of the posts would be greater in the former instance.

The level of immersion in the picture argument I can appreciate. I also appreciate that to an intent and purposes if you're watching from the same relative distance, things will pretty much be the same.

BUT: the fact remains that the smaller screens have denser more detailed pictures. That isn't a conclusive argument against bigger displays - the immersion arguably more than compensates for the (relative) loss of detail for most folks. But that doesn't mean that there is an inviolable rule that 'bigger is better' or conversely that 'small is beautiful' - merely that as you increase or decrease your screen size you're trading one kind of good with another. Where you want to draw the line (detail or immersion, or somewhere in the middle) is a matter of personal choice.

As I said, this isn't meant to be combative. I could, thank you very much, have a projector and massive display if I wanted (we're not all on the poverty line and living in cardboard boxes in the middle of the road in Europe, you know ). I personally prefer a smallish TV and greater detail. But no way am I saying this is the only correct answer. And for those who like large displays, then more power to your elbow (or is that too Brit a phrase? It's a compliment, I promise you!).

Edit: Whoops, my analysis was wrong. You were comparing 1080p to 720p.

Sorry

Sorry, but it isn't a conclusive argument period. Within a given distance, a larger screen will give you a more immersive experience, as long as you don't sit inside the optimum. At the optimum, you lose no "detail" at all. Resolution in optics is the viewing angle at which you can resolve an individual element. A bigger pixel at a greater distance has the same resolution as a smaller pixel at a lesser distance. If you define the "optimum" as the point at which you can't sit any closer without resolving a pixel element, then the resolution (and thus the detail) of the screens are exactly the same if seen from the optimum. You just get to sit farther back with the larger screen.

Which is what I said - it isn't a conclusive argument! The immersive experience will be what lights a lot of folk's candles. All I'm saying is that isn't true for everyone - some will prefer the greater detail. This isn't better, it isn't worse, but it is equally valid.

Of course, if it were the case that pixel density was a constant across all display sizes, then the bigger displays win hands down. But as it is, IMHO it's a balance, with no single correct answer.

LOL, that's exactly what you're saying. You seem to be under the impression that if a picture is smaller but retains an identical resolution it is somehow "more detailed" as a result. That's just not how it works. A 1920x1080 image is going to have the exact same amount of detail in it at any size. Given equal resolutions across screens, the pixel density of a display only effects the size of your image, nothing more.

If what you said is true, then the graph of distance vs screen size would curve upward as screen size increased. If you suddenly got a less detailed picture as the screen size increased, then the optimum distance would not increase at the same rate as the screen size. But the graph of each resolution is arrow straight. The ability to discern the most detail (the "optimum") is a linear constant, not an increasing curve.

Edit: I had my x and y axis wrong. The curve would be upward, not downward.

My schwartz is bigger than yours!

I agree.

The distance to the screen makes all the difference:
If I'm 2 inches from the set, an inch fills up half my field of vision.
If I'm 2 feet from the set, an inch looks like an inch.
If I'm 20 feet from the set, an inch looks like 1 pixel.
If I'm 200 feet from the set, an inch is barely visible.

What matters is the number of pixels in the total image (and how dense they are). The number of pixels and the density are independent of the total screen size.
A large screen could be 1080P with good density (no screen door effect), while a small screen can be 480i with a screen door effect.

The rest is a function of how close you are to the screen.
Too close and you can see the pixels. Too far and it doesn't fill enough of your field of vision. Most people want it to fill a reasonable portion of their field of vision to get that "immersion", "real theater" feel. You can do this either with a big screen or by sitting close to it; however most people want to watch their screen with friends and the more people watching the farther back you have to be. If it's just you you can get away with a 20" screen if you're willing to sit 12 inches away. If you have friends you're going to need to go much bigger.

Brian, that is a big room you've got.

I do understand what andrew is getting at, because it happened to me when I saw a movie digitally projected in a theater and I was sitting in the front row. What he's trying to convey is that it is possible for the pixels to get so large, because of screen size, that you can resolve the individual pixels with your own eye.

But it is a function of pixel size, seating distance, and how good your eyes are.

Here is an exerpt from a recent article that is related to this subject that I read on CNET.com. I would give you a link to the original article, but the system won't let me yet. I am still under the 10 post minimum. The article is titled "720P vs. 1080P HDTV - The final word" if you are interested in looking it up.


9. Side by side, how do 720p and 1080p TVs match up in head-to-head tests?
We spend a lot of time looking at a variety of source material on a variety of TVs in our video lab here at CNET's offices in New York. When I wrote my original article two years ago, many 1080p TVs weren't as sharp as they claimed to be on paper. By that, I mean a lot of older 1080p sets couldn't necessarily display all 2 million-plus pixels in the real world--technically, speaking, they couldn't "resolve" every line of a 1080i or 1080p test pattern.

That's changed in the last couple of years. Most 1080p sets are now capable of fully resolving 1080i and 1080p material. But that hasn't altered our views about 1080p TVs. We still believe that when you're dealing with TVs 50 inches and smaller, the added resolution has only a very minor impact on picture quality. On a regular basis in our HDTV reviews, we put 720p (or 768p) sets next to 1080p sets, then feed them both the same source material, whether it's 1080i or 1080p, from the highest-quality Blu-ray and HD DVD players. We typically watch both sets for a while, with eyes darting back and forth between the two, looking for differences in the most-detailed sections, such as hair, textures of fabric, and grassy plains. Bottom line: It's almost always very difficult to see any difference--especially from farther than 8 feet away on a 50-inch TV.

I said so much in a 2006 column I wrote called The case against 1080p, but some readers knocked us for not looking at high-end TVs in our tests. But the fact is, resolution is resolution, and whether you're looking at a Sony or a Westinghouse, 1080p resolution--which relates to picture sharpness--is the same and is a separate issue from black levels and color accuracy.

Our resident video guru, Senior Editor David Katzmaier, stands by what he said two years ago: The extra sharpness afforded by the 1080p televisions he's seen is noticeable only when watching 1080i or 1080p sources on a larger screens, say 55 inches and bigger, or with projectors that display a wall-size picture. Katzmaier also says that the main real-world advantage of 1080p is not the extra sharpness you'll be seeing, but instead, the smaller, more densely packed pixels. In other words, you can sit closer to a 1080p television and not notice any pixel structure, such as stair-stepping along diagonal lines, or the screen door effect (where you can actually see the space between the pixels). This advantage applies regardless of the quality of the source.



What I intrepret this to mean is that for most people at normal viewing distances, it is very difficult, if not impossible, to even see the resolution difference between even a 720P display and a 1080P display. Where the difference can be seen is when viewing at closer distances than the hypothetical "normal" distance. As David Katzmaier says in the above article, the real advantage to 1080P is the "smaller, more densely packed pixles."

Now, what this means to me personally is that when I buy a new HDTV, I will look very closely at the "price vs. performance" equation and see if it makes sense to pay the extra price for a 1080P set, and the extra pixels that most of the time I would not "see" any benefit from. At this point I have not decided if it will or not, time will tell. However, my guess is that by the time I end up getting a new set this decision will have been made for me as there will probably not be very many, if any, 720P sets even left on the market to even choose from.

Later,

Treker