Why 1080p has no merit, apart from maybe reducing SDE. - Page 2

I honestly can't believe that. I just had a 1080p and 720p pj in my room for 2 days doing side by side on the same screen. I can not see any more detail at any distance. Screen door is a factor, but not detail. I simply have to say that I completely disagree with what you're saying based on my own in room comparison on a 106" screen.

I would suggest you try a simple 6.75Mhz test pattern available from DVE or Aria DVD as a start. (note some of the difference could be caused by the difference of scaler inside difference projector, but we have tried connecting a 3000+ dollars scaler to some lower cost 720p projectors to compare it more fairly with 1080p projector with better scaler inside)

For real image, you may want try to compare at the texture of objects (skin, stone, cloth....) from high resolution sources.

P.S. If you are trying comparing some sharp objects - their difference are actually quite small, but texture is a very different story.
Projectors compared are Optoma HD81, HD72, HD70, HD7100

it's not the same when you're up close to something; when the light from a pj screen has to get 13' to your eyes, it's not equal to a monitor which only has to travel a foot or two; you loose image quality

Oh, I did not understand. But to me it is irrelevant. If I can't see a difference in a movie on BluRay or HD-DVD, our best sources for films, then it's not a difference to me. I wouldn't use the pj to view pictures.

I don't watch test patterns, I watch movies. And if I can't see a difference in a movie (on BluRay or HD-DVD), then it's not a difference to me.


I've compared faces, clothes, stones, everything. I cannot see any more detail in the 1080p projector image between Epson 700 and Epson 1000.

Maybe there is a difference in DLP models like Optoma, but I am skeptical since I could not find it with LCD.

I can see stair-stepping on my 720p DLP when playing HD DVDs or Blu-ray movies. That clearly (pun intended) means I need a 1080p projector, plain and simple. I sit at 1.2-1.3 screen widths from the screen (92" diagonal, 80x45" 8-9 feet from my eyes), and I would have an even bigger picture if I could achieve it. When I go to movie theaters, I sit as close as my dates/friends can handle.

It's a matter of DPI, if you ask me.

Let's look at some data. I will compare the DPI of a 4:3 PJ and that of the 22" CRT aforementioned.

The dimensions of a 90" 4:3 screen are 72" x 54" (width x height).

The dimensions of the screen for the 22" CRT is 17.6" x 13.2", assuming that 22" is the viewable size, and that we have a 4:3 ratio tube.

Let's assume that the PJ used for this comparision has an adjustable resolution, since the object is to determine which format would appear best.

We are comparing 1280 x 720 to 1920 x 1440. The former is a 16:9 ratio, and the later is a 4:3. Right away, we see a problem with the comparison. 1080p is 1920 x 1080, not 1920 x 1440. But still, there's more to consider, especially pertaining to aspect ratio. Let's get to this in a moment.

Assuming we run the 1280 x 720 resolution stretched to fit the entire viewing area of the CRT and PJ, we get a DPI of 72.7 x 54 (width x height). If the image were not stretched vertically due to the 4:3 aspect ratio the DPI would be 72 x 72. For 1920 x 1440, which is a 4:3 ratio resolution, we get 109 x 109 DPI.

The DPI for the PJ is much lower, of course, because we have a bigger image. For the 1280 x 720 resolution we have a DPI of 17.7 x 13.3. If we allowed no vertical stretch, we'd have an ideal DPI of 17.7 x 17.7. For 1920 x 1440, we'd have a DPI of 26.6 x 26.6.

Theoretically speaking, we'd see an improvement in quality for both resolutions. In reality, both mediums have a limitation in the DPI that can be displayed. For PJs, this is easy to overcome; simply use a larger DLP chip and magnify the image less to attain a higher resolution and DPI given a constant image size. The CRT however has a similar problem but cannot be so easily overcome. The main specification that is holding us back is something called dot pitch. Most monitors have a dot pitch of around .25 mm, but can range anywhere from .21 mm to .28 mm. Dot pitch can be simply explained as the size of an idividual pixel. This means that the CRT would have a maximum ideal resolution of around 1788 x 1341 for a .25 mm CRT, which is far below that of 1920 x 1440. In fact, you'd need around .22 mm CRT to really get the most from 1920 x 1440. If you exceed the ideal resolution, the image will become fuzzy as pixels will overlap.

So now we're left with a few questions, the most important of which, IMO, is this: What is the dot pitch of the monitor used in the comparison of resolutions? Also, there was a discrepancy in the aspect ratio of the resolutions used. Was the 1920 x 1440 resolution used to display a movie that was not stretched vertically and similarly, was the 1280 x 720 res. not stretched to the height of the monitor?

My conclusion is this: It is far easier to see pixelation given a low DPI image, as opposed to a high DPI image. Considering the VERY high DPI of 1920 x 1440 resolution on such a small CRT, I find it very hard to believe that anyone with average eye sight would notice the increase, simply because of the limitations of the CRT itself and/or the eyesight of the observer. The PJ however would display a far more noticeable increase in resolution because the lower DPI due to larger screen size would allow for more detail to become visible to the observer, especially so with larger sized screens.

I don't know if this has been covered in the following posts, but I think you are misunderstanding what is being suggested by THX recommendations.
Putting it simply, a viewing arc of 36 degrees is the *minimum* not the maximum. In other words it is the back of the theatre. In experiments with 7k displays in Japan arcs of 100 degrees are utilized by some.

As to your experiments with screenshots Bob Sorel has said it much better than I might. See here http://www.avsforum.com/avs-vb/showt...&&#post8972257

Here is a recent discussion in the Blu Ray Players forum re the value of 1080
http://www.avsforum.com/avs-vb/showt...6&page=2&pp=30

I can readily see the difference between 720 and 1080 source into my 720p LCD though the pj 's scaler is throwing away 1/2 the pixels. I look forward to upgrading my pj.

I sit about 2.5 screen heights, which if you measure rez like SMPTE as line pairs per screen height, is the way to determine viewing distance - our eyes resolve equally vertically and horizontal. This translates to about 1.35 for screen width on a 16:9 screen. With 2.35 material (I've a Constant Height setup) I am sitting about 1.1. which is *within* (not the *farthest*) what THX recommends .

DarinP's post from the above thread says it succinctly

Noting this article http://www.carltonbale.com/blog/2006...p-does-matter/ it is apparent that for most the value of 1080p only begins to become apparent once you move to >36 degree viewing arcs so it is no surprise that you are not noticing differences. It is the premise that 1.5 that is optimum that creates this mistake.

The value of 1080, and with luck beyond, is the ability to increase screen size or viewing ratio.

ted

We need 1080p so the high-quality 720p PJs drop some more!
:-)

I'll take an IN78 for $1000 (... I know... not going to happen for a while... :-D)

I'm truly shocked at how much prices have dropped. And I think the new JVC RS1 being as low as it is will be like a bomb going off in front projection if it holds up to be as good as purported.

How is anyone going to try to sell a 1080p anything above $6k? Maybe 3 chip DLP, but that to me would still be a tough sell.

I would never have guessed you could actually buy D6 1080p LCD for under $3500 this year. And I never thought you'd be able to get a Pearl for barely more.

Sweet times for front projection.

If 1080p looks about the same as 720p everyon should all just get an IMX lens for their 720p unit. Though the one clear thing 1080p units definitely seem to have over most of the 720p units is contrast. I think 1080p would be beneficial for me since I want to sit around 1x the width.

it only makes sense to me that 1080p will...(if not already) be able to deliver a better image than 720p....this may but an unnoticable difference for smaller screens but the larger you go the more pixels you need to have the same vivid depth and resolution to the eye. true thier isn't much out there right now to properly utilize this added res but it only makes sense now with this new digital technology (and manufacturers realizing the money to be made off this "gotta beat the Jones" market) that the technology will not by any means stop at 1080p and eventually things will be higher res. So.... as the source material gets better the average screen size will also grow just as it has in the past...I do believe there would have to be a more realistic feel to a 1080p image at say 100" from a real 1080p source than a 720p image from a 720p source... Coming from the large format graphic arts and photography scene this only makes sense as I see everyday what a lower res photo looks like when you blow it up...even with the best rip money can buy it just looks worse than a higher res image printed on a higher resolution (higher DPI) printer, there's just more to see period.
I also aree that the difference is getting more minimal as you go over the 720p threshhold at the smaller (under100in) sizes but will a real 1080p image look any worse downscaled to 720p ? Also wouldn't a higher res picture show smoother gradients in color and light as well as SDE? Better fill and less SDE is an advantage here and an important one so why are we complaining about this..? No one's forcing us to convert to 1080p and have no reason to be ashamed not to have it... Its my opinion thats there really ins't enough advantages to going 1080p just yet. But I do believe I will want to in the not to distant future because If I listened to everything I read here I would have paid more heed to the guys who said the difference between 480p and 720p was not noticable....(ya right..maybe on a 13" screen)I would be in the dark. There are a lot of factors here eyesight being one thats overlooked in a lot of opinions...I for one think dvd's look better scaled up to 720p on my new setup as opposed to my old 480p setup. On the otherhand I also think my 480i sat feeds look a bit softer because thier just isn't enough pixels there to trick my eyes..bottom line the more pixels you have to work with the less you will notice the differences in deviations....but this is a good thing and not somthing to fight because with higher res displays...the content will be forced to a higher average quality. And that still important to those of us who want more than bragging rights.

Then they should look at this and tell my why they think the area governed by the word "recommended" suggests only 36 degrees of viewing arc.


I think the idea of our displays replicating reality is amusing. Its a discussion that has been undertaken since the early 60's in the photo arts. Any capture device will mitigate reality - it is artifice. It is now basic in high school media courses that we should use our minds to see, not our eyes. How can anything that is edited by a creator be "real"? Personally I don't want to be looking at "reality" I want to look at art. Reality involves far more than any display can convey. You want reality, take your dog for a walk.


I was hoping you would note Bob's description of how the process from file to display through the various types of massaging is enough in itself to change an image. The very usage of capture in JPEG is enough to change the nature of "reality". Frankly its one of the reasons I'm pissed that I no longer can get a point and shoot that still has RAW mode files.

If its reality you are after, I think you should look elsewhere than pixel count.

ted

One demo we recently added is feed a HD70 (low cost 720p projector) with a 1080p signal (from PS3) displaying it normally at 720p and then use the overscan mode to zoom in the picture to display the extra details available on 1080p.
(since most Blu-ray DVDs are 2.35:1 or wider, a large part of the image is still viewable, black bars are also thinner)

At overscan mode 4 (16% zoom) or the bigger Native mode, extra details are easily noticable by viewers.

Yes, viewer are effectively watching at much less than 1.5x and part of the image on two sides are cropped off, but why not if it is enjoyable to do so?

I do recommend 720p users upgrading to 1080p to get a bigger screen. 2.35:1 screen with anamorphic lens if they can afford so.

Our 2.35:1 anamorphic lens demo are usually demonstrated at 1.2 to 1.4x screen width distance. (So far no audience has complained they were sitting too close)

I do agree that most viewers may not be able see all the details from a 1080p image until they are at 1.2x or less, but seeing more details than 720p is quite possible at up to 1.7 or 1.8x especially when viewing test patterns or scene audience are familiar with. Beyond that is getting tough, for normal people with 20/20 vision. (there exists people such as fighter pilots who have better vision than 20/20 though)

PS The higher ANSI contrast available on 1080p DC3 DMD do helps to make difference in details more noticable.

I have to wonder: as we become more accustomed to HD material as the norm on higher quality larger displays, whether the average viewer will become more sophisticated and more readily discern the differences and subtlety that 1080 source/display can bring. Would the average viewer now used to DVD, give up his player for VHS?

ted

Isn't that the point of higher definition? High definition is for big screens. Why did high definition get brought up in the first place? Because those huge 50+ inch standard definition RPTVs looked like crap. It was like watching television through window blinds. (I suppose scan lines can be considered a form of screen door)

At 1 screen width, 1080p isn't something that "might have merit", as was stated in post #47, but something which would show definite improvement because it would eliminate screen door up to .25 widths. As it stands now, I can still discern some screen door, especially on solid colors such as is found in anitmated / computer generated movies, and on games.

If 1.5x screen width seating distance is a hard and fast rule which should never be violated lest George Lucas sends storm troopers to your home to force you to watch "Howard the Duck" repeatedly, then why IMax? Why are people paying to essentially sit closer than 1 screen width?

I think that's the whole point of the highest of the high definition (in terms of widely available consumer electronics - not 4K uber-high end stuff) Being able to sit CLOSER without seeing pixels.

The 1.5x rule only has merit for all the videophiles who would never violate a published standard, and who don't purchase anything which doesn't have the THX logo on it, and who actually had a friend use a tape measure to ensure the front of their eyeball was *exactly* 1.5X screen widths from the screen. You know who you are - the one with the vice attached to the seatback.

For all the rest of us traitorous heathen scumbags out there who aren't worthy to even utter the letters "THX", REJOICE! Soon you will be able to get a 1080p projector once they become affordable, get the biggest dang screen you can fit into your room, and move the sofa closer than 1.5 screen widths! For all the rest of you who never break the rules set by people who have more initials after their names than your entire family tree, or who get motion sickness whenever they even see ship in a bottle, stick to 720p and 1.5 screen widths. Or better yet, save money, get a $400 20" LCD television, and sit 1.5 screen widths from that.

Edit:

Here's some suggestions for topics you may want to post in some other forums.

Why a NVidia 8800GTX has no merit, apart from maybe increasing FPS
Why a Porsche no merit, apart from maybe increasing MPH
Why a Hybrid car has no merit, apart from maybe increasing MPG
Why an Intel Core 2 Extreme has no merit, apart from maybe increasing FLOPS

Why are you always saying might? You seem to have more of an agenda than your stated purpose. I know it will provide me with a better picture. I do have a DarkChip3 projector, the Mitsubishi HC3100. And I do see the screen door at 1 screen width. There's no maybe or might about it. I see it. And I've also seen a 1080p projector (Sony VPW100) on a 123 inch Stewart Firehawk in a very well set up room. I had to get to about 1/4-1/2 screen width to see the screen door. No maybe or might about it. So as a DC3 owner who has seen both technologies, I think I could possibly consider myself to be qualified enough to say that at one screen width, 1080p WILL benefit me. Not maybe or might.


How much is most? 99%? 51% I wonder - how many of them would sit closer if screen door was no longer an issue? Are they sitting that far away for reasons of overall viewing experience, or are they sitting that far away so as not to see the screen door?

I repeated your experament, and at 1.5 screen widths (2.25, actually, to make up for the part of the picture cut off the sides of the monitor), I do notice a subtle increase in clarity between 720 and 1080. At 1 screen width, the difference is definite, not maybe or might.

Also, in your original post, the first two paragraphs after the first two introductory sentences were an argument with regards to transfer quality, not with regards to resolution. So I think your primary beef is with the post-production departments of every major film studio. I recall in Season 7 of Stargate, there is a 2-part episode called "Heroes" in which the show switches between the standard point of view of the show, and a "video camera" point of view. In the video camera point of view the show could seem to some to look more "real". Because in this particular point of view, it looks as if no post-production went into altering the raw footage. That can also explain how a home movie shot on a HD video camera could look better than film studio transfers - post production was signifigantly different from what the film industry does.

wel said I was gonna say somthing about how how it would be similiar to saying why buy a corvette or cadillac when a chevy cobalt can do the maximum speed limit too. There are simply many reasons its more desirable. And I guess In one of those people violating those rules currently with my 720p 108" screen bing about 11 to 12 ft from my head. and if I sit at the other end of my sectional I'm only 6 ft away Maybe I should buy a bigger house instead of using that merit from a 1080p projector?

I have a UWXGA (2560x1600) 30" monitor that I'm typing this on. Being totally hard up for HD as I am living in India, I downloaded an Apple Trailer in 720p and 1080p. I know some people say these are soft; looks amazing to me. Haven't used my HD-DVD player yet so I can't say if it's better or worse. Anyway the point of my test was to scale the 720p image up to the same size as the native 1080p (yes I can have 2 1080p images on my desktop at the same time - AR wasn't 16:9 so they were skinny and fit easily) and then did click frame advancing to see a difference. I'd say the 1080p was marginally more detailed.

I know it's hardly a scientific test, but the same monitor showing the same source encoded at the two resolutions basically confirmed what I'd already suspected: 1080p is better, more detailed (esp on a huge screen) but it's a diminishing return. I'm THRILLED with my purchase of a $900 720p DLP and will upgrade in 2-3 years when 1080p DLPs are the same price. I don't think I'll get as great a performance gain as going from 576p to 720p and hd-dvd at the same time like this upgrade cycle, but I think it'll be worth doing - might also go to a larger screen (at around 98" now).

Jones_Rush - just checked out this thread. Very interesting! I think that many of the points you make are very valid.

However, as far as visual irritation over SDE I'm probably in the top 1%. I spent several hours comparing a 720p LCD unit with the Mitsubishi 5000.

Even at 2 to 3 times screen width SDE was still interfering with my enjoyment. However, at 1 to 1.5 times with the Mitsu 5000, the picture transformed to a completely different class.

I would say that for 90% of the video material I watch, something like a Sanyo Z5 will produce an excellent picture with just as much resolution as my Mitsu 5000. On the best video material, the Mitsu will cross over to the "open window" effect. A 720p projector can't quite get there.

However, the biggest point is that for folks like me, the resolving power between the two technologies is really not the issue. Its whether or not the projector I'm watching presents a non-fatiguing, non-digitized picture. 720p, especially LCD or DLP does not do that. 1080p LCD and SXRD does, and that makes all of the difference in the world.

The problem is I'm a basket case when it comes to SDE. It was the Epson that I was comparing to the Mitsu 5000 several weeks ago when I was in buying mode.

I had to go to 3x screen width to completely remove the effect, which will not work in my setup.

Having said that, I am amazed of just how good some of the under $2K 720p units are. This is a great time to be buying a two piece front projection system!

Brian