720p 1080i 1080p ???

[picopir8]

So, if this is the case, I believe you are much better off (I feel) to let your TWC box output to both 1080i and 720p, especially if you have a TV with a native resolution of 1080p...  

This is the only time (having a 1080p set) when it might be adventageous to have the upconversion take place in the TV and not in the cable box.  However, switching channels will change protocol that the TV an cable box use to communicate and cause the picture to freeze/flicker in the process.  If you have a 1080i set or 720p set, it will still be better to have the cable box do the conversion.

[TPK]

This is the only time (having a 1080p set) when it might be adventageous to have the upconversion take place in the TV and not in the cable box.  However, switching channels will change protocol that the TV an cable box use to communicate and cause the picture to freeze/flicker in the process.  If you have a 1080i set or 720p set, it will still be better to have the cable box do the conversion.

Ya...  I have a DLP projection with a 720 native resolution (NR)...  So really it didn't matter all that much for me...  The only real advantage of setting the TWC cable box to output both resolutions as opposed to just 720p I think would have been that I trust my TV to do the de-interlacing of the 1080i broadcasts a bit more than I trust the TWC cable box to do it...

de-interlacing can be (should be) handled with some processing to remove those "interlacing artifacts" that can be introduced into a picture when it stitches the two half-frames together into one..  Doing this can lead to descrepencies in the picture due to the fact that adjacent lines are actually 1/30th of a second out-of-sync with each other...  The common example used to illistrate the problem is to imagine a pitcher throwing a fast baseball from the side... Without a good de-interlacer you would notice a bunch of motion blur of the baseball because half of the ball (every other line) is slightly ahead of the other half....

I'm sure that TWC/Scientific Atlanta/etc doesnt put a whole lot of effort or money into a good de-interlacer in their boxes...  It probably just combines the two half frames and is done with it...  TV manufacturers care a little bit more about image quality and probably invest more in a good de-interlacer that watch out for motion-blur and compensate for it....

Another issue that has to be addressed is, of course, downscaling (from a 1080 picture to a 720 picture)...  A good downscaler should know how to downscale and avoid those moiere (sp?) effects and to smooth out those jagged lines, etc...  Again, I would put more faith into my TV to do the downscaling than the cable box...

For these reasons, even though I had a 720 NR set, I still set the TWC box to output both resolutions, even though I had to put up with some delay when switching from a 720p channel to a 1080i channel...

Even so, the quality difference between these 2 methods (letting your cable box or your TV de-interlace and downscale) is probably neglagable to barely noticable most of the time...  So in reality, in the case where the TV has a 720 NR, most folks are probably better off setting the box to a 720p output to match their television....

However if you have a TV set with 1080 NR (and most HD TVs being sold today have 1080 NR) then I think you really might be missing out if you force your box to one resolution or the other....  Either your going to give up the higher resolution of a 1080 picture, or your going to give up the higher frame rate and progressive qualtiy of a 720 picture...

Im not sure what you mean by a "1080i" set, unless you are referring to CRTs or CRT projection type sets that may still project the image in an interlaced manner with the electron gun and may not really have a specific native resolution..  Or maybe you a referring to the fact that a lot of 1080 NR sets are unable to accept a 1080p signal via its inputs...

Interlace/progressive largely describes the type of broadcast, and not really the television set itself...    Marketing will sometimes advertise a TV set as "1080p", but typically this means is that the TV has a 1080 NR and will accept a 1080p signal via its inputs...

Almost all HDTVs sold today (and in the past number of years) are either direct display flat panels (like LCD/Plasma) or micro display projections (like DLP/Lcos/LCD Projection/etc..)..    All of these have a true native resolution, and will display the image as a seamless whole, which means that they have to de-interlace the picture before displaying it as a whole picture...  Only sets that still use "scan lines" (the soon to be dead CRT) can get away with displaying the picture in an interlaced manner (electron gun scans the odd lines, goes to the top, and then scans the even lines, etc.)...

Even if a 1080 NR set would be unable to accept a 1080p signal via HDMI or component (can component even do 1080p?), it should still accept either a 1080i signal, de-interlace, and attempt to use the higher resoluton of the display to show all/most 1080 lines of resolution and display at 30fps; or it should accept a 720p signal, attempt to upscale the image to its 1080 native resolution and display at 60fps..  It doesn't make sense for a micro-display or a direct display to interlace a 720p signal internally...

Long and short of it is, I think if you have a 1080 NR set and a TWC cable box, your are much better off  and getting the highest quality picture out of your TV by enabling both resolutions in your cable box...

If you have a 720 NR set and a TWC cable box, you are just somewhat better off and getting the highest quality picture out of your TV by enabling both resolutions in your cable box...

Either way, by enabling both resolutions, you are going to have to put up with some delay in your picture as your TV has to re-sync from one resolution to the other when switching between channels of different resolutions (much like how a computer monitor as it changes resolutions)...

My personal opinion is that I would rather attempt to get the best picture qualtiy possible, even if it means putting up with the re-sync when switching channels...

In reality almost all cable networks are 1080i anyways (only the sports channels use the 720p standard), so unless Im switching to/from ESPN (or Fox or ABC) from something else, the sync delay doesnt happen most of the time anyhow...  "Channel surfing" isn't an issue for me either, since Ive stopped scanning up and down the dial with channel up/down a long time ago and use the guide exclusively now (which can be unbelievably painful on these u-verse boxes)..

Anyhow, that is my opinion...