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811 Owners... Is your 811 outputing high def when set to 720p?


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#1 OFFLINE   andrew_ballew

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Posted 09 January 2004 - 12:27 PM

All you 811 owners with 720p display devices.... are you acually getting an HD output when you select 720p on the 811? I am not. My display device says it is receiving 720p, but the picture is standard def. At least one other person on the AVSforum has the same issue. What about others?


Andrew



EDIT

When I say standard def, I mean standard def on HDNET, DISCOVERYHD, ETC. ETC. Flipping between 720p and 480p shows no difference. Its that bad. The only way to get the pristine HD signal is to output 1080i, which would be fine except for the fact I have a native 720p display device with a poor scaler.

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#2 Guest_gpflepsen_*

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Posted 09 January 2004 - 12:40 PM

My 720p is high def. It looks HD.

I don't really understand your problem. Your TV is telling you it is getting a 720p signal, yet you don't think the quality is good enough for HD? Which channel are you seeing this on?

#3 OFFLINE   greylar

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Posted 09 January 2004 - 12:46 PM

Yea that is very confusing to me as well. To be truely HD these things must happen. (This is a generalized way of putting it so you techies don't hammer me on it. I'm just trying to make it easier to understand.)

1. Filmed in HD
2. Broadcast in HD
3. Received in HD
4. Displayed in HD

If the receiver and the display are both in HD then you its either not broadcast or filmed in HD. I don't really see how the receiver could be the problem.

EDIT: After reading the other posts I guess it is the receiver. It appears that when scaling from 1080 to 720 the picture quality is degraded somewhat.

#4 Guest_centauri_*

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Posted 09 January 2004 - 12:46 PM

All you 811 owners with 720p display devices.... are you acually getting an HD output when you select 720p on the 811? I am not. My display device says it is receiving 720p, but the picture is standard def. At least one other person on the AVSforum has the same issue. What about others?


Andrew



I have a Sammy 467 DLP that displays 720p. It will accept a 1080i signal and the TV pix is HUGELY better when I set the 811 to output 1080i. There is more info in the 1080i signal that the Sammy can use and I'd say if your set can accept a 1080i input, USE IT! You'll be glad you did. I was confused at first about the up and down conversions. Should I set the 811 to what the TV displays??? WRONG! You can see the difference on the HDNet "eye chart." I can read the bottom 2 lines with a 1080i and not even close with the 811 set to 720. Let the TV do all the work and give it the best signal you can.

#5 OFFLINE   willy

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Posted 09 January 2004 - 12:56 PM

Centauri,

YOu are making the assumption that 1080i is "better" than 720p. This is a highly debated issue!

Going from 720p -> 1080i is not "up-converting". Its just converting. Both are HD. (going from 480i to 720p, for example, is upconverting). 1080i is maybe the best visually to you, on your particular set up with your eyes. But "the best you can get" is not a clear choice of 1080i.

The rule of thumb would be to set your reciever output to what your set natively displays. The less "conversions" the more pristine the image.

#6 OFFLINE   andrew_ballew

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Posted 09 January 2004 - 12:58 PM

My display device is a Sanyo PLV-Z2 with a native resolution of 720p. Unfortunately, the scaler in the Z2 is not the best, so I want the 811 to do the scaling for me. This also will keep any native 720p material (ESPNHD) from being scaled twice, further impacting the quality of the signal.

THE PROBLEM is.... the 720p signal being output by the 811 looks like upconverted standard definition. It is not high def. I know what high def looks like. As a matter of fact, the DirecTV box that I replaced with the Dish 811 output a beautiful 720p picture to my Z2. To get a high definition picture, I have to set the output on the box to 1080i, which is NOT optimal since the Z2 has a poor scaler.

Bottom line... at least my particular 811 ( and one other that I know of) does not output a high definition signal at 720p. To me it looks like HD content is being scaled from 1080i to 480p first, then to 720p. While watching an HD channel like HDNET, flipping from 720p to 480p looks exactly the same.

Centuari...

you do realize that your Sammy DLP is scaling the 1080i signal to 720p, right? So your options are to set the 811 to 1080i and let your TV scale it to 720p, or set the 811 to 720p and let the 811 scale 1080i to 720p.

I submit to you that since you see such a drastic difference ( you should not, since the only difference should be in the quality of scaling-usually minor) your unit has the exact same problem.

#7 OFFLINE   willy

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Posted 09 January 2004 - 01:10 PM

To me it looks like HD content is being scaled from 1080i to 480p first, then to 720p. While watching an HD channel like HDNET, flipping from 720p to 480p looks exactly the same.



HMMMMM.... Maybe thats why Centauri quoted seeing such drastically better results with 1080i output vs. 720p. Only he attributed it to just 1080i quaility over *true* 720p quality.

#8 Guest_gpflepsen_*

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Posted 09 January 2004 - 01:11 PM

Using the 811 on a DLP display presents a few problems. The native resolution of the display doesn't match very many broadcast. Only ESPN HD and ABC HD are 720p. With the 811 set to output 1080i on ABC and ESPN, the signal goes through two conversions; 720p>1080i and then 1080i>720p. Not a good situation for PQ. The best selection of 811 output would be 720p for these stations.

On the broadcasters putting out 1080i, the scaler in the display devise would dictate the 811 setting of 720p or 1080i. From my experience with my Sammy DLP, the TV's scaler does a better job of converting 1080i to 720p. In this case, having the 811 set to 1080i is the best choice.

#9 OFFLINE   andrew_ballew

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Posted 09 January 2004 - 01:17 PM

Using the 811 on a DLP display presents a few problems. The native resolution of the display doesn't match very many broadcast. Only ESPN HD and ABC HD are 720p. With the 811 set to output 1080i on ABC and ESPN, the signal goes through two conversions; 720p>1080i and then 1080i>720p. Not a good situation for PQ. The best selection of 811 output would be 720p for these stations.

On the broadcasters putting out 1080i, the scaler in the display devise would dictate the 811 setting of 720p or 1080i. From my experience with my Sammy DLP, the TV's scaler does a better job of converting 1080i to 720p. In this case, having the 811 set to 1080i is the best choice.



If the scaler in the Sammy is better than on your 811, then yes, set to 1080i. You would still have to flip it to 720p for ABC or ESPNHD if you wanted optimal picture quality since you would not want it scaled once at the box and once at the TV.

BUT, in my case these relatively minor differences from scaling are not the issue. Again, there is no difference flipping between 720p and 480p on your usual suspects of HDNET, DiscoveryHD, etc...

#10 Guest_gpflepsen_*

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Posted 09 January 2004 - 01:28 PM

I don't have any 720p material to view and judge right now. But from my recollection, I do get a better picture with 720p when viewing ESPN HD. I can't comment on ABC HD being that their tower collapsed last July.

I do switch my 811's setting between 1080i and 720p to match the source material.

#11 Guest_gpflepsen_*

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Posted 09 January 2004 - 01:33 PM

...Flipping between 720p and 480p shows no difference. Its that bad. The only way to get the pristine HD signal is to output 1080i, which would be fine except for the fact I have a native 720p display device with a poor scaler.


So which scaler is doing a better job of 1080i>720p, your TV or your 811?

#12 OFFLINE   andrew_ballew

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Posted 09 January 2004 - 01:47 PM

So which scaler is doing a better job of 1080i>720p, your TV or your 811?



Well obviously at this point the TV, since the 811 for whatever reason is not outputting anything close to high definition on 720p.

It a lot worse than typical scaler issues, so at this point comparing scaling really isn't possible.

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Posted 09 January 2004 - 03:00 PM

I just spent 15 minutes watching Discovery HD's (1080i) Insectia on Spiders. I toggled through 1080i, 720p and 480p.

1080i was a very good picture, what I consider HD.

720p was not quite up to the 1080i's setting, but it was still pretty good. I consider this HD but can see the difference in the two scalers.

480p was noticeable in its lack of resolution and was definitely a poorer quality than both HD settings. It was still a good picture though.

I can tell an improvement when watching ESPN HD in 720p over 1080i. I know in this instance the 811 is doing HD in 720p.

#14 Guest_centauri_*

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Posted 09 January 2004 - 03:52 PM

My display device is a Sanyo PLV-Z2 with a native resolution of 720p. Unfortunately, the scaler in the Z2 is not the best, so I want the 811 to do the scaling for me. This also will keep any native 720p material (ESPNHD) from being scaled twice, further impacting the quality of the signal.

THE PROBLEM is.... the 720p signal being output by the 811 looks like upconverted standard definition. It is not high def. I know what high def looks like. As a matter of fact, the DirecTV box that I replaced with the Dish 811 output a beautiful 720p picture to my Z2. To get a high definition picture, I have to set the output on the box to 1080i, which is NOT optimal since the Z2 has a poor scaler.

Bottom line... at least my particular 811 ( and one other that I know of) does not output a high definition signal at 720p. To me it looks like HD content is being scaled from 1080i to 480p first, then to 720p. While watching an HD channel like HDNET, flipping from 720p to 480p looks exactly the same.

Centuari...

you do realize that your Sammy DLP is scaling the 1080i signal to 720p, right? So your options are to set the 811 to 1080i and let your TV scale it to 720p, or set the 811 to 720p and let the 811 scale 1080i to 720p.

I submit to you that since you see such a drastic difference ( you should not, since the only difference should be in the quality of scaling-usually minor) your unit has the exact same problem.


There is no doubt in my mind or my wife's mind that the display is better on everything when we set the 811 to 1080i. And it makes sense. There is more info in a 1080i signal. 50% more lines to start with. I think the answer is that the Sammy throws out the stuff it can't use better than the 811 does when the 811 is set to 720p. And it doesn't matter if it's on a component cable or DVI. As a matter of fact I disconnected my DVI and went back to component because the pix quality was indistinguishable and when my Sammy is set to DVI, I can't change the aspect to anything but widescreen. So when I watch ESPNHD it was always stretched. But with component input I can select "normal" aspect and then it's tolerable to watch in it's 720p.

#15 OFFLINE   willy

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Posted 09 January 2004 - 04:10 PM

I dont follow--- 1080i is 2 passes of 540 lines. 720p is one pass of 720 lines. So in a single pass the 720p has "more lines". I can see the argument about the 811 possibly erroneously downconverting to 480p then to 720p- or just a bad scaler to 720p. What I dont buy is that 720p is just that much worse. Its your tv's native resolution- if it were that bad 1080 would look just as bad.

Dont forget your TV has a native 720p resolution, it cannot display anything other than 720 lines. Period. You have a fixed pixel display. If you feed in 1080i, you will always see 720 on your screen. Read that last sentence again.

#16 OFFLINE   tdigden

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Posted 09 January 2004 - 04:35 PM

I have the 811 connected to my Sharp XV-Z9000U projector which also natively supports 720p and compresses 1080i. The picture looks great in either 720P and 1080I. I noticed that on pictures look better when showed in its native format so whenever I watch ESPN HD which uses 720P..the picture looks better in 720p over 1080i. I was a bit surprised that the picture looked better in 1080i with 1080i programming (CBS playoff football) considering my projector only supports 1280 x 720 (enough for true 720p but not 1080i) and uses what it calls "intelligent compression" to display 1080i.

#17 OFFLINE   andrew_ballew

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Posted 09 January 2004 - 04:59 PM

I have the 811 connected to my Sharp XV-Z9000U projector which also natively supports 720p and compresses 1080i. The picture looks great in either 720P and 1080I. I noticed that on pictures look better when showed in its native format so whenever I watch ESPN HD which useds 720P..the picture looks better in 720p over 1080i. I was a bit surprised that the picture looked better in 1080i with 1080i programming (CBS payoff football) considering my projector only supports 1280 x 720 (enough for true 720p but not 1080i) and uses what it calles "intelligent compression" to display 1080i.



What it sounds like based on all posts that even with 811's that are working properly, the scaler in the 811 is weak. Unfortunately, I consider my problems to be worse than just a poor scaler.

#18 OFFLINE   andrew_ballew

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Posted 09 January 2004 - 05:01 PM

There is no doubt in my mind or my wife's mind that the display is better on everything when we set the 811 to 1080i. And it makes sense. There is more info in a 1080i signal. 50% more lines to start with. I think the answer is that the Sammy throws out the stuff it can't use better than the 811 does when the 811 is set to 720p. And it doesn't matter if it's on a component cable or DVI. As a matter of fact I disconnected my DVI and went back to component because the pix quality was indistinguishable and when my Sammy is set to DVI, I can't change the aspect to anything but widescreen. So when I watch ESPNHD it was always stretched. But with component input I can select "normal" aspect and then it's tolerable to watch in it's 720p.



1080i doesn't look better because 1080i has more resolution to start with... it looks better because the scaler in your TV is better. Either way you are going to get a picture scaled to 720p. Its just a matter of where the scaling occurs, and which does a better job.

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Posted 09 January 2004 - 05:12 PM

Saying that 1080i has 50% more information than 720p can use is misleading. In the same sense I can say 1080i can only use half the information from 720p.

Theoretical resolution of 1080i is greater than 720p. In the real world though, 720p offers higher resolution.

In 1/60 of a second, 720p paints a 720x1280=921,600 pixel picture.
in 1/60 of a second, 1080i paints a 540x1920=1,036,800 pixel picture.

So, at best, you can only say 1080i offers a 12% higher rsolution.

If you want to get into actual perceived resolution, color resolution, dynamic resolution, 720p outperforms 1080i. Not to mention that 1080i's horizontal resolution is more on the order of 1400 pixels.

Was that Pandora's box that was just opened? :)

#20 OFFLINE   Jerry G

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Posted 09 January 2004 - 06:29 PM

Saying that 1080i has 50% more information than 720p can use is misleading. In the same sense I can say 1080i can only use half the information from 720p.

Theoretical resolution of 1080i is greater than 720p. In the real world though, 720p offers higher resolution.

In 1/60 of a second, 720p paints a 720x1280=921,600 pixel picture.
in 1/60 of a second, 1080i paints a 540x1920=1,036,800 pixel picture.

So, at best, you can only say 1080i offers a 12% higher rsolution.

If you want to get into actual perceived resolution, color resolution, dynamic resolution, 720p outperforms 1080i. Not to mention that 1080i's horizontal resolution is more on the order of 1400 pixels.

Was that Pandora's box that was just opened? :)


This is too simplistic. You have to take into account the amount of motion going on in a frame/field. With a completely static image, 1080 has significantly more resolution than 720. The pixels aren't moving, so it's 1080x1929 and not 540x1920. As the amount of movement increases, there are more pixel changes during the two fields of a 1080 signal and effective resolution will begin to drop. And given all of that, most observers still feel that 1080 gives a better picture with sports events than 720 does, but I'll admit that with sports, it's a very debatable issue.




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