SD vs HD, a link to a great site with picture comparisons. (1 Viewer)

[Vader]

That, I think we can all agree, is an advantage of going to the theatre that never will be replicated in HT..!

 

[JeremyErwin]

I'm sure you could rig up something with butt-kickers.

Somewhere, I've read that from an acoustics perspective, the best seat in the house is about 2/3 back.

 

[Andrew Bunk]

I'll have to measure my viewing distance. I know I'm farther than 1.6 screen lengths, but not much over 2. I believe my screen length is just under 50 inches. I want to say the distance to my eyes from the scrteen is about 8.5 feet, so 102 inches.

When I first got the set in my apartment, I didn't have as much room so I actually was sitting more like 84 inches away. It still looked great, but I found that it actually tried my eyes out. I find I prefer to have the whole frame in view without needing move my eyes very much to see one side or the other. I also tend to sit farther up in a theater. Generally where stadium seating is involved, I try to sit where my eyes are even with the middle of the screen, both horizontally and vertically.

I understand if I move closer to my screen at home the image will degrade accordingly. But I still feel that I am seeing a great amount of detail with many SD-DVD's, even at 2 screen lengths. As much as HD? No way.

I was bit more cavalier with my spending last year, but being a homeowner now I have to reign it in a bit. In the near past I might have bought both formats just to check them out. But I need to wait and see who will win here. I wish it was cut and dried for Blu-Ray, but I fear the smaller cost of HD-DVD could away the average consumer.

Just like Beta was the better format, people still went for VHS.

Although I have to admit I am tempted by Pioneer's Blu_ray players. Plus if the reviews of the gear show they do great upscaling, that might be reason enough for me to jump in early.

I can't wait for guys like Dave Boulet and others around here to get their hands on this gear so we can get some honest evaluation instead of PR stuff being done at the demos.

 

[Nils Luehrmann]

I strongly disagree with both of these statements and for several reasons.

First let's momentarily ignore the fact that the size of a screen does not determine how much of your field of vision is filled with the image, thus determining how much extra detail you may or may not see.

It is estimated that at least 90% of the projectors currently being used in home theaters today have a resolution smaller than 1280x720. Some of the best selling home theater projectors past and present have a 854x480 resolution like InFocus 4805 & LS110, BenQ PE5120, Sharp DT-100 & XV-Z10E, Toshiba TDP-MT200 & TLP-ET1, Epson MovieMate & PowerLite, Optoma H27 & H31 & MovieTime, NEC HT410, Dream Vision, Hitachi EDPJ32, Cinego D-1000, and ViewSonic Cine1000 among others.

Now I'll guarantee anyone with a 20" WXGA monitor, let alone a 50" 1920x1080 RPTV will easily notice far more detail from an HD image (and any resolution image mind you) than one projected on a 144" screen from any of those projectors listed above, or the countless SVGA and XGA projectors.


Now more to the point, it is a terrible myth perpetuated by the industry to sell larger screens, that the larger the screen the more detail you will see.

First, it is the resolution of the display that determines the specific amount of detail you can see, not the screen size.

Secondly, it is how close you are to the screen, NOT the screen size that determines how much of that detail provided by the display you will actually notice.

Thirdly, even when screen sizes and distance to width ratios are equal, unless you don’t have 20/20 vision (naturally or corrected), you will be able to notice the difference between SD and HD even from 20’ away from a 40” TV. If you want to test this, just drop by your local BestBuy, CC, Fry’s, etc. I’ve taken a few doubters to my local BB and they all left amazed at how much better the HD looked even from more than 5x screen widths away!


OK, now about the myth of large screens…

Sadly, many first time front projector owners get sold on the notion bigger is better and buy enormous screens that ruin what could have been a wonderful image.

You see, the larger the screen the more light you lose, and as almost 90% of all home theater projectors have less than 500 lumens when properly calibrated for video means that not only are you not seeing any more detail than someone sitting the same distance to width ratio from a 50" screen than on a +120" screen, but the image on the 120" screen suffers from lack of proper illumination.

There are other reasons why large screens can, and often do degrade the quality of the image.

This topic unfortunately comes up far to often due to the myth about "large screens", so I'm sure this wont be the last. :frowning:

For even more specifics on this topic here are a couple links to explore:


The physical size of an image has very little to do with how easy it is to notice the quality, or lack of quality of an image.

Not only doesn't the size of the screen determine the viewable size of the image, but the plain fact is that the larger the screen the quality of the image almost always suffers.


BTW: I do speak with some experience as a longtime and current owner of several large screens, including a 98" screen in my dedicated theater, 165" screen in our 3-car garage bay for large group screenings, and an even larger outdoor screen when the weather permits.

The value of a large screen is that it allows you to have wider and multiple rows of seating without drastically changing each person's viewing perspective.

But make no mistake about it, the larger the screen, the more it compromises the picture quality.

 

[DaViD Boulet]

If light output is adjusted (more for a larger screen) and viewing angle kept constant, then a large image does NOT compromise picture quality.

In fact, *all things being equal* (we're not talking about micro-perf screens etc.), the larger image, even with the same viewing angle of a smaller one, will "feel" more like a real movie...in the same way that watching a movie at the theater at 1.6 screen widths can "feel" more dramatic than watching at 1.6 screen widths at home. This is because in addition to our field-of-vision (viewing angle), our brain triggers a sense of "awe" when we know we're seeing something large (which our eyes know based on focal length and angle of stereoscopic sight).

Now, what you say is perfectly true about being able to see detail etc....that's all about resolution and viewing-angle...I totally agree.

But beyond that there are still *benefits* to going large, based on these other aspects of visual perception that are distinct from field-of-vision and detail.

Just as long as you can keep the image just as bright (a bulb and projector-design issue, not a big-versus-small issue), you're not losing anything...only gaining!

-dave

 

[Brent M]

Good posts, David and Derek.

 

[Shawn Perron]

This would be more correct in a perfect world where your projector had unlimited resolution and perfect optics. Each projector is going to have a certain screen size that will present the best image it is capable of. Due to technical limitations, making your screen larger then this can turn what would be small annoyances into blatantly annoying visual anomolies. For instance, being able to see the pixel structure of your projector isn't exactly the best way to replicate the movie experience.

As time goes on and they perfect these technologies (as well as lowering the costs), obviously your statement will become more and more true.

 

[DaViD Boulet]

Shawn,

that's why I said "viewing angle kept constant".

Again...size has nothing to do with any of the issues you mention...that's all about VIEWING ANGLE. That's what Nils is primarily addressing in his post.

"Keeping viewing angle constant" means that as you make your screen larger you move your seating position farther back so that the ratio of screen-width-to-viewing-distance never changes. In that scenario...which I've *clarified over and over* (sigh...) pixels would be no more visible than the SAME PROJECTOR with a smaller screen viewed from a closer distance.

And to repeat , regarding brightness (which you didn't mention but in case someone is thinking about it), this is a projector-design/blub issue and not one of "big versus small" screen sizes. If a projector was designed to properly light a 100" screen with the same brightness as an optimally-lit 50" screen, then there's no compromise.

If a projector can't properly light a 106 inch screen, then it's not designed to perform properly with that size screen...which is an issue of that particular projector design and screen size and screen material. Naturally anyone interested in investing in a front projection system needs to investigate to determine what combination of factors works best for them. For some, the drama of a large screen is worth the trade-off in brightness given how bright a projector in their price-range might be able to drive a 106" screen (me). For others, brightness might be more important so they buy a dim projector but use it with a smaller screen...or if they have the $$ they buy a projector with more lumens to drive the 106" screen with the brightness they desire.

If this concept of viewing angle is hard to understand for anyone I suggest taking a break from posting for a short while and visualize this until it clicks:

Placing your head 15 inches away from your computer screen that is 10 inches wide is the *same viewing angle* as sitting 150 inches away from a screen that's 100 inches wide. Assuming that the two displays have identical resolution and quality, the image "looks the same" to your eyes...you see the same detail, the same pixels, everything.

That's what Nils is saying. That's why I always qualify my remarks with "viewing angle", "wide angle" or "screen width/viewing distance ratio".

What I'm suggesting is that in terms of seeing the detial in the picture and evaluating the quality of an image this is good enough.

However, because our stereoscopic vision detects "size" based on the focal length required in your eyes and the angle of sight between them, the 100 inch wide screen is perceived with a great senese of "awe" because your brain *knows* that it's bigger...even if it fills the same field of vision on your retina and even if it has the same level of resolution as the smaller 10 inch screen viewed from 15 inches away.

 

[Nils Luehrmann]

A few problems with that (post 65 that is)

• The larger the screen the more likely you will have to have a micro-perf screen or else suffer from poorly placed speakers.
• The larger the screen, the greater the chance of screen gain uniformity issues.
• While we are beginning to see some projectors with adjustable light output, almost all of them still can not produce more than 500 lumens when calibrated. Use your zoom feature or better yet move your projector back and forth and watch how much better the smaller image looks compared to the larger on the same screen maintiang the same D:W ratio. I've done this many times with many visitors to our home and unanimously everyone agrees that going above 100" the image suffers, certainly with anything around 1000 lumens and using a 1.3 gain screen.
• You can use higher gain screens, but these also compromise picture quality with uniformity issues and "sparkles".

What you see is what fills your field of vision, nothing more. Furthermore, going back to the point of this discussion, and that is which allows you to see more detail, a smaller screen or a larger - not the physiological impact of "feeling" like you are watching a film in a massive theater.

After all, look at my sig. I LOVE THE THEATER EXPERIENCE! But I've had enough experience to know "feel" doesn't equate to better picture quality. It can... like seeing a quality 70mm print in a properly designed and maintained theater, but it more commonly does not.

By sitting closer to the physical screen, versus sitting further back (maintaining the same D:W ratio), you will also see more detail as the human eye is most efficient at shorter distances, corrected or not.

Unfortunately, things are not all equal, and is why larger screens often sacrifice picture quality for real estate.

 

[DaViD Boulet]

Nils,

again all the points you mention are implimentation-specific. If a projector is designed to have more-than-enough brightness (like a 3-chip DLP projector) then as long as it's able to be the *right* brightness at your chosen screen-size...there is NO COMPROMISE. The fact that making the image smaller with the same projector might look even brighter doesn't mean that the 100" image is a "compromise"...if the 100" image is designed to be optimally-bright, then one could just as easily argue that the smaller image is *too* bright and therefore a compromise in the other direction.

Let's not try to pull issues like micro-perf into the equation since I'm being clear that I'm NOT talking about issues like that...which clearly compromise image quality (regardless of "screen size", I might add). Were I to build a dream HT system with a 50 foot screen I would do so without a micro-perf screen.

Nor am I suggesting that problems associated with high-gain screens are the answer. BRIGHTER PROJECTORS are the answer and completely negate all of "brigtness" issues you're putting forward...and they are linked to projector *design* (and price) and not a fixed problem of "big" images.

Heck, for that matter in 10 years you might have a 120 inch direct-view LED screen with enough brightness to melt the ice cubes in your soda. Let's not try to associate brightness with "big" as though the two are one and the same...they are not.

And I'm *agreeing* with your point that your eyes see the same level of detail in an image based on viewing angle alone...we agree. What I'm saying is that the larger screen with the same viewing angle is perceived by your brain to be "larger" and therefore may have more emotional impact because your brain has triggers *other* than field-of-vision to judge size and distance...the focal length of your eye and angle of focus between them being two. If you disagree with this, then you are telling me that watching my 10" computer screen from 15 inches away "feels the same" to my brain as watching a 100" screen from 150 inches away. It does not, even though the detail and resolution are identical and both images fill the same area on the retina.

dave

 

[Nils Luehrmann]

Very good post (68) Dave, and this part especially bares repeating:But let us be sure we all understand... "Awe" does not have ANY effect on picture quality. It effects our emotions, good or bad, but doesn't impact the amount of detail we can see in an image.

Furthermore, by having less "Awe" you might be less distracted by the theater and or screen, and have more attention placed on the image thus allowing you to again see more detail.

 

[DaViD Boulet]

Absolutely correct...I hope I haven't indicated otherwise.

I would say that *all things being equal* (resolution etc) sitting 15 inches away from a 10 inch computer screen would reveal the SAME image *quality* as sitting 150 inches from a 100 inch screen. Right on. Reviewing a DVD and evaluating it's image quality should produce the same results in both scenarios.



However, from an emotional-impact standpoint, who would want to *watch* a DVD movie at 15 inches away from a 10 inch screen...even if you're just watching it by yourself? The emotional-impact of the *larger* screen is greater...simply because it's *larger* and your brain knows that it is...

And to be clear, viewing-angle *also* affects emotional impact so it's not just one or the other. For instance, watching a 10 inch screen from 15 inches might be more emotionally involving than watching a 100 inch screen from 50 feet away.

But viewing angle kept constant...the bigger screen feels more involving.

 

[Nils Luehrmann]

Bottom line, and getting back to the original insinuation that on smaller displays (under 60") it's very difficult to spot the difference between SD&HD...

This is absolutely not true.

I, and those I have shown demos to can all attest to seeing significant improvement in PQ from SD to HD, even on a 24" monitor from 5x screen widths away.

Now just because there is a difference, even a dramatic one doesn't mean everyone should and will throw out their SD DVD's in disgust, nor will most likely be jumping on board the HD train this early in the game. It just means that it isn't the size of your screen that will determine if you can see a difference or even how great of a difference you will see.

It will be dependent on the type of display you have, your viewing distance, and most important of all, if the cost is worth it, after all, if HD hardware and software were free, everyone would get it. Even those with 7" portable displays.

 

[Andrew Bunk]

Dave mentioned a 30 degree viewing angle. I thought I remember seeing a site like this, but does anyone have a formula for determining the distance to sit from a screen to obtain a certain viewing angle?

 

[Dave Mack]

Andrew, the LOTR PAL discs are still sped up of course, so the tempo is indeed 4% faster but they are pitch corrected so the music doesn't sound a 1/2 step higher. And the voices sound accurate too. I know it's still not authentic technically but the PQ ia SO much better (and no 3/2 pulldown judder with PAL progressive) so for me and Bjoern the PAL discs are the way to go. But one day we'll have them on HD so it's moot anyways.

d

 

[JediFonger]

derek,

life is full of compromises. when i first fell in love with watching films, it was always in the cinema. Nice, crisp sound, with freshly installed THX speakers, etc. when i came home and watched VHS or regular TV, the quality is just a compromise that we (at that time) live with. low-res sux, plain and simple. So, vinyl sux, audio casette tape sux, VHS sux, etc.

Sure, it's an l337-ist 'tude, but hey, I'd rather feel like a 9 year old than what I actually am . DVD was better, but i remember reading about HD before DVD spec was even finalized in the mid 90s. Oh man, I salivated after that! I don't have more than 50-60 movies that I re-watch or pull out and watch a scene regularly. I could have thousands of DVDs like many of you folx, but I was waiting for HD discs since the mid 90s! I would've loved to have HD audio And video by the 90s or earlier. Technology is too slow for me!!!

Let's extrapolate a compromise scale of 1-10 with 10 being the feeling of MOST compromise and 1 being the least compromise. VHS is a 10 because it's the first popular consumer video playback system (from content creator through consumer) that actually worked in the market. It gets moving images onscreen, but nothing more than that. DVD was somn like a 7 because DVD reproduced a CONSISTENT image that doesn't degrade every time you play it back. HD/BR? I'd have to say a 1. why? It's the closest, most practical method of reproducing highest quality image @home front. Granted, it isn't film, the cost of reproducing that @home is beyond the reaches of everyone (99.9999%).

What really shocks me is the level of compromise that most of you would adhere to. Did NONE of you ever feel the vision of the future that way I did? Ah well. Here today, gone tomorrow right? SO you live with VHS, DVD and fool yourselves into thinking that it's a good image when it's "CRAP" in every sense of the word.

Nils,

If you bought your FP in the last few years, 90% of them are more than 1,000 ANSI lumens (I assume you mean using calibration DVDs like AVID, etc.) after calibration. If it ISN'T 1,000+ lumens, do you have a device that scientifically measures that or are you just reading theories? I wouldn't worry about that nowadays. It's bright enough for me.

I agree with you on some but don't agree with you on the other. Even if you don't go all the way to 1080i/p and stick with 720p, the visual difference between that 720p and 480p doesn't just reside in line-resolution, but the resolve of visual quality (like those motion artifacts&distortion around edges). For example, take FOTR. Cap from DVD and zoom in around Gandalf's hat contrasted against the green field. You'll see a technical limitation of SD-DVD. That's regardless of screen size. You do the same with HD version of the same movie. Super sharp!

 

[DaViD Boulet]

YiFeng,

I feel the same way that you do on almost every point you make. I also dreamed of HD media since the days of laserdisc...a "movie in my home" that would have the breathtaking clarity, resolution, and integrity of a real projected film-print. 1080P can make that happen.

I'm a visionary too. When Joe Kane was talking about putting 720P HD video on red-laser DVD I criticized him for "lacking vision" because his thinking was stuck in a CRT-infrastructure world and he couldn't see past that to the day of affordable fixed-panel projectors that could easily bring 1080P images to the average HT enthusiast. In no way does a 1280 x 720 image constitute the transparency Joe Kane apparently thought was "good enough" for our movies...as you say, the pixel-stair-stepping around hard-egdes at the 720P level is still visible from a 1.6 seating distance! I'm all there on the visonary thing...

But if VHS were a "10" (badness) and 1080P was a "1" (best), I'd personally rank a well-mastered DVD more like a "3"...closer to the side of where we want to be than where we don't want to be.

And while I wouldn't call a well-mastered DVD "crap" that's not to say that there might be specific titles that I choose not to watch at all until I can view them in 1080P glory. I've already started to sell off vast portions of my DVD collection that I KNOW I will wait to enjoy until I can see them in HD!

dave

 

[Nils Luehrmann]

Of course what you just said about the visual difference between HD & SD doesn’t only reside in resolution, but also in artifacts and distortion, is one of the reasons why even with small non high definition displays, you can still see the difference in quality between SD & HD.

 

[Vader]

Oh yea, that’s the way I watch movies: with my face right up against the screen. Next time you go see a film in the theater, walk right up to the screen and do the same. Guess what? It is not still ‘super-sharp’! And that’s at 4k lines of resolution. Sorry to break up your paradigm, but does that mean that even full res 35mm stock doesn’t cut it?

 

[Mark Lucas]

Sorry but the 4k lines of resolution needs to be thrown out of the arguement, unless you're viewing the negative, a timed IP, or show print that was made from a 4k DI. The average theatrical print is way way lower in res and also color fidelity. Think one hour photo job.

SD DVD looks like crap on a 40ft screen and on a 24" screen, both at two screen heights away. 1080p looks great. The end.