# 1080i/ 720P



## tomallison24 (Dec 10, 2008)

I just moved to Dish from TWC. I have the 722 K and a 58" 1080P Samsung.
I haven't seen the picture improvement from cable to Dish that I expected, may be slightly worse(still good). I noticed the installer had the dish set to 480P in the HDTV part of the setup menu. I changed this to 1080i. Any difference between this and 720P. On TWC it showed the stations input(either 720P or 1080i. I'm guessing that my TV is picking the right one no matter which one I choose but I'm not sure. Any help or comments to let me understand would be appreciated. Thanks.


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## girdnerg (May 17, 2007)

480p is the default. The installer just didn't change it. Dish does not have native pass-thru, so whatever you set it to (in your case 1080i) is what everything will be converted to before passing to your TV. Then your TV will up it to 1080p.

You'll just have to test between 480p, 720p, and 1080i to see which looks better to you.


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## tnsprin (Mar 16, 2003)

Note also that its channel dependent. Essentially a 1080i source on a 1080P should always look best on at 1080i. A 720P source may look better at 720P or at 1080I. 480 SD may look best at 480P or at 1080i (rarely at 720P on a 1080P set).

Lots of us hope that Dish will finally offer so called Pass-thru. They mentioned it perhaps 3 years ago but never followed through.


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## Jeff_DML (Feb 12, 2008)

easy to add passthrough so I assume there is a reason why they havent added it. Probably dont want service calls from people asking why the channel gets all scrambled looking when they change channels. 

They should add a secret key sequence to enable it like TiVo does for other features


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## simulated (Jun 6, 2006)

Jeff_DML said:


> easy to add passthrough so I assume there is a reason why they havent added it. Probably dont want service calls from people asking why the channel gets all scrambled looking when they change channels.
> 
> They should add a secret key sequence to enable it like TiVo does for other features


I don't know of *any* tvs that could properly show dish's 1440x1080i resolution at it's corrected aspect ratio, stretched to fill the 1920x1080i regular picture size. So I very much doubt you'll see a pass through anytime soon, if never at all.


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## tnsprin (Mar 16, 2003)

simulated said:


> I don't know of *any* tvs that could properly show dish's 1440x1080i resolution at it's corrected aspect ratio, stretched to fill the 1920x1080i regular picture size. So I very much doubt you'll see a pass through anytime soon, if never at all.


Actually quite a few can display 1440x1080 even though not usually mentioned in the TV specs. But by "pass-thru" it is generally assumed we are meaning send a 1080i source as 1080i even if it first does it first has to stretch the pixels to 1920 before sending it. Send 720P as 720P, 480p as 480P, etc. It would be even nicer if this was configurable i.e you select what each of the major vertical rates is output as.


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## Jeff_DML (Feb 12, 2008)

simulated said:


> I don't know of *any* tvs that could properly show dish's 1440x1080i resolution at it's corrected aspect ratio, stretched to fill the 1920x1080i regular picture size. So I very much doubt you'll see a pass through anytime soon, if never at all.


I thought the HD-lite was dead, you sure they are still doing that? I thought that was done by DirecTV a few years ago and they have stopped. Still prefer passthrough for removing the frame rate conversion p->I or i->p


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## HarveyLA (Jun 8, 2006)

simulated said:


> I don't know of *any* tvs that could properly show dish's 1440x1080i resolution at it's corrected aspect ratio, stretched to fill the 1920x1080i regular picture size. So I very much doubt you'll see a pass through anytime soon, if never at all.


The format of 1080i does not change when video is filtered to remove the sharpest details. It is always going to be 1920x1080, and 30 interlaced frames/sec. Reducing the quality to an effective resolution of 1440x1080 cuts down the bitstream rate, allowing more channels on a transponder. However it has nothing to do with aspect ratio or stretch modes. The picture is still the correct shape.

On 720p: Most viewers aren't aware of the fact that 720p (which has several options on frames/sec.) displays 60 complete images/sec. on live telecasts (or recorded telecasts of live events.) And the lines are scanned in the correct order. 1080i has only 30 images/sec. and their lines are transmitted out of order (first the odd lines from a given frame, then the even lines. They must be reassembled in your TV set in the correct order.) 720p allows for smoother action on a sports event where there is fast action. The complete picture is being refreshed 60 times a second.) So, if you are watching sports on ABC, FOX or ESPN (which transmit in 720p) and your Dish receiver is set for 1080i, the picture will be converted to a 30 frame/sec. image, throwing away every other frame. Try resetting your Dish box to 720p and you will see the visible difference. In addition, you will avoid the interlace/deinterlace process, which might degrade the picture further, depending on the quality of your set's deinterlacer. That is why Dish should give us native pass-thru.


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## PghGuy (Oct 13, 2006)

HarveyLA said:


> The format of 1080i does not change when video is filtered to remove the sharpest details. It is always going to be 1920x1080, and 30 interlaced frames/sec. Reducing the quality to an effective resolution of 1440x1080 cuts down the bitstream rate, allowing more channels on a transponder. However it has nothing to do with aspect ratio or stretch modes. The picture is still the correct shape.
> 
> On 720p: Most viewers aren't aware of the fact that 720p (which has several options on frames/sec.) displays 60 complete images/sec. on live telecasts (or recorded telecasts of live events.) And the lines are scanned in the correct order. 1080i has only 30 images/sec. and their lines are transmitted out of order (first the odd lines from a given frame, then the even lines. They must be reassembled in your TV set in the correct order.) 720p allows for smoother action on a sports event where there is fast action. The complete picture is being refreshed 60 times a second.) So, if you are watching sports on ABC, FOX or ESPN (which transmit in 720p) and your Dish receiver is set for 1080i, the picture will be converted to a 30 frame/sec. image, throwing away every other frame. *Try resetting your Dish box to 720p and you will see the visible difference.* In addition, you will avoid the interlace/deinterlace process, which might degrade the picture further, depending on the quality of your set's deinterlacer. That is why Dish should give us native pass-thru.


Don't disagree with anything you say however the "visible difference" part is very subjective, while there may be a difference other factors also come into play to determine if it is that visible. For me and my 720p (actually 768p), there is not that much difference visible difference at all between settings of 1080i and 720p on sports.


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## HarveyLA (Jun 8, 2006)

HarveyLA said:


> your Dish receiver is set for 1080i, the picture will be converted to a 30 frame/sec. image, throwing away every other frame.


On second thought, I'm not sure if every other frame is tossed out, or if the Dish receiver takes one 720p frame for the "odd" interlace field, followed by the next 720p frame for the "even" interlace field. That might be even worse! (sorry for the lengthy explanation, but the bottom line is: *without native pass-thru, you lose picture quality watching 720p/60 converted to 1080i/30 in the Dish receiver, converted to 1080p/60 in your set!)*


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## HobbyTalk (Jul 14, 2007)

PghGuy said:


> Don't disagree with anything you say however the "visible difference" part is very subjective, while there may be a difference other factors also come into play to determine if it is that visible. For me and my 720p (actually 768p), there is not that much difference visible difference at all between settings of 1080i and 720p on sports.


Many 768p sets first upscale to 1080 before they downscale to 768p as it is easier to get 768 out of 1080 then it is to go from 720 direct to 768. I know my Panny does this, not sure about the Pioneer. So in this case, 1080i may in fact give a better picture since the set has one less conversion to do.


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## HarveyLA (Jun 8, 2006)

PghGuy said:


> Don't disagree with anything you say however the "visible difference" part is very subjective, while there may be a difference other factors also come into play to determine if it is that visible. For me and my 720p (actually 768p), there is not that much difference visible difference at all between settings of 1080i and 720p on sports.


My comments were based only on a 1080P TV, not 720P. Mine is a 46" 1080p.
On my set, there is more clarity to the picture- it looks more "live."


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## simulated (Jun 6, 2006)

HarveyLA said:


> The format of 1080i does not change when video is filtered to remove the sharpest details. It is always going to be 1920x1080, and 30 interlaced frames/sec. Reducing the quality to an effective resolution of 1440x1080 cuts down the bitstream rate, allowing more channels on a transponder. However it has nothing to do with aspect ratio or stretch modes. The picture is still the correct shape.


Video Size: 1440 x 1080 (AR 20:11)

that there VIP box you got there does that there stretching to fill your 16:9 tv.

the whole reason for my post is that if 1440x1080i was passed to your tv, it would look like crap.

square pixels or something?


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## HarveyLA (Jun 8, 2006)

simulated said:


> Video Size: 1440 x 1080 (AR 20:11)
> 
> that there VIP box you got there does that there stretching to fill your 16:9 tv.
> 
> ...


Very interesting. That would indicate a major alteration to a non-standard HDTV format. But how do you know they are doing this?


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## simulated (Jun 6, 2006)

HarveyLA said:


> Very interesting. That would indicate a major alteration to a non-standard HDTV format. But how do you know they are doing this?


The channels I've seen, past and present that dish decided to not encrypt have always been either 1280x720p or 1440x1080i, heck 480x480i for the eastern arc customers for SD content.

Passing a frame size of 1440x1080i "as is" might work on some tvs, but I'm sure most would have issues.


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## tnsprin (Mar 16, 2003)

HarveyLA said:


> Very interesting. That would indicate a major alteration to a non-standard HDTV format. But how do you know they are doing this?


This rate is in the standard ATSC standard and authorized for broadcasting from satellite but not for Over the Air broadcasting. It is also used by many video cameras. It is not required to be handled by TV's although some handle it. Chips used to handle this in Video cameras, DISh receivers, etc. support them and in some cases the same chip is used in Tv's, which is why they can also support them. Some TV's even have Card slots for media, and therefore felt they had to support them.

Lots of other oddball video standards exist and often can be handled by TV's. e.g 720P30 and 720p29.97 rather than 720P60.

Lets be happy Dish is not playing around with these, and only using the 1440x1080I.


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## PghGuy (Oct 13, 2006)

HobbyTalk said:


> Many 768p sets first upscale to 1080 before they downscale to 768p as it is easier to get 768 out of 1080 then it is to go from 720 direct to 768. I know my Panny does this, not sure about the Pioneer. So in this case, 1080i may in fact give a better picture since the set has one less conversion to do.


I didn't know that. Thanks


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