HR10-250 Output to 1080P Set

[stumacdo]

Hi all,

I've got a new Samsung 1080P set on the way, and I'm just curious about what is the best resolution to feed it from the HR10-250. I know you should match the output to the set's native resolution, but since the HR10-250 only goes up to 1080i, what is the ideal setting ? Thanks in advance.

[Guindalf]

The HR10 can be set to 1080i or 720p. The only way to answer the question is to look at the PQ and see which you prefer. There is no way to output 1080p (as you already know).

I suspect that 1080i will be the de facto setting, but I don't have a 1080p TV to test it on.

[AstroDad]

I thought you were supposed to match it up with what resolution the show is broadcast in, not what your TV is capable of? If nothing is broadcast in 1080p, there is no use for 1080p right now, right?

[AbMagFab]

I have a Sony 60" 1080p set, and always use 1080i. There is a lot more picture detail on 1080i then 720p, on the 1080i source signals (especially CBS).

While TyroneShoes will chime in and say that 1080i doesn't mean more pixels (actually, he doesn't say that, but I don't really understand the distinction he's drawing), it seems logical that, when setting the HR10 to 1080i, and using a 1080i source, you're getting to see more pixels than if you watched a 1080i source with the HR10 set to 720p.

In any case, viewing it is the deciding factor, and for me on my Sony, there's a significant difference in picture detail and quality when set at 1080i versus 720p.

That being said, you need to be close enough to your TV for your eyes to even resolve the 1080p pixels. I site about 8-9 feet from my 60" TV, which is about the right range for the size.

What size TV did you get? And how close will you be sitting?

(Also, I didn't think the Sammy's supported 1080p input anyway, do they?)

[Lee L]

I would guess it is much easier for the TV to double it than to change from 720p to 1080p which will require some funky math to make work.

[AbMagFab]

I would guess it is much easier for the TV to double it than to change from 720p to 1080p which will require some funky math to make work.

?

If you mean deinterlace a 1080i signal, that all depends on the TV. The Sony XBR's do a great job at this, coming amazingly close to 1080p (pretty much indistiguishable).

If you mean scaling a 720p source to 1080i, that really depends on the TV, and the receiver. The question is whether the HR10 can convert from 720p to 1080i better than the TV. In my case, the TV actually does this better, but not good enough to warrant me switching from 1080i to 720p whenever I go from CBS to ABC.

I wish DirecTV would let Tivo upgrade these things already, so we could get a Native option.

[stumacdo]

I have a Sony 60" 1080p set, and always use 1080i. There is a lot more picture detail on 1080i then 720p, on the 1080i source signals (especially CBS).


That being said, you need to be close enough to your TV for your eyes to even resolve the 1080p pixels. I site about 8-9 feet from my 60" TV, which is about the right range for the size.

What size TV did you get? And how close will you be sitting?

(Also, I didn't think the Sammy's supported 1080p input anyway, do they?)

The newer Samsung DLP models (HLS-xx87/8) are now 1080P native. Mine is going to be a 56" model, and I sit @ 9 feet from the set. The newer sets have 2 HDMI inputs which are nice if you have the HR10-250 and an upconverting DVD player and don't want to deal with a HDMI Switcher. I've got one from Monoprice and it gets a little fluky from time to time.

[hoopsrgreat]

The newer sets have 2 HDMI inputs which are nice if you have the HR10-250 and an upconverting DVD player and don't want to deal with a HDMI Switcher. I've got one from Monoprice and it gets a little fluky from time to time.



Or you just get a receiver with a few HDMI inputs and you are all set. I have the smasung HLR-6178 and it also has 2 HDMI inputs by the way.

[dave3]

the best test is to try the dfferent modes and see which shows a better picture. Since you do not know which, hr-10 or samsung, has the better scaler inside. Chances are that 1080i would be the best results with a 1080i source since no scalling will be needed, but deinterlacing can still be a factor.

Most likely the difference between the two settings will not be visible to the naked eye.

my 2 cents.

dave

[kjnorman]

I thought the best idea with 1080P sets is to set the Tivo to native - ie output the signal based on what ever it is broadcast at.

This way the TV can maximize the resolution of both 1080i and 720p outputs.

For example:

Say the output is 1080i then this is easy for the TV to line double each half frame to 1080P.

Say the output is 720P then the TV simply scales from 1280x720p to 1920x1080P.

Now if you fixed the Tivo at 1080i, if you have a 720P source such as ABC, then the tivo will first interlace the progressive frame - thereby throwing detail away and then it will scale it to 1920x1080i. You TV will then line double this. A similar thing happens if you convert 1080i to output as 720p from the tivo. In the end you have lost detail.

So, the simple rule is leave it as native!

[rminsk]

I thought the best idea with 1080P sets is to set the Tivo to native - ie output the signal based on what ever it is broadcast at.
...
So, the simple rule is leave it as native!The HR10-250 does not have native pass through.

[TyroneShoes]

I thought you were supposed to match it up with what resolution the show is broadcast in, not what your TV is capable of? If nothing is broadcast in 1080p, there is no use for 1080p right now, right?
I don't think that either one of those concepts is really true.

The only real reason there is an ability to switch the output is to match the display as best as possible, because not all displays would be compatible with just 720p or just 1080i. It's really a set-it-forget-it setting, although to appease those who just can't understand that distinction, there is a handy remote code to make it easy to change, and to make them feel better.

As far as matching that display goes, it would make sense to always feed a 720p output to a 720p native display, as then any rescaling from 1080i would be done internal to the Tivo rather than at the display, and this would avoid rescaling 720p content to 1080i for Tivo output and back to 720p at the display. The double rescale is probably pretty invisible, but not necessary. Only if the rescaler in the set were significantly better than the one in the Tivo would there be a reason to do it that way, and since the Tivo has a state-of-art rescaling capability, that is less than likely.

Likewise, it would make sense to always feed a 1080i output to a 1080p native display, as then any rescaling from 720p would be done internal to the Tivo rather than at the display, and this would avoid rescaling 1080i content to 720p for Tivo output and back to 1080p at the display. In that case, you could lose some resolution occasinally during the double rescale.

For a 768p-native set it could be a flip of the coin, as you can't really avoid a double rescale. Logic then would tend to say use 1080i output, as that would again avoid any possible resolution loss of passing through 720p mode. But, it really depends upon how deinterlace is handled. If the set doesn't handle it well (bobs rather than weaves), you will see jaggies when in 1080i Tivo output mode that you will not see with 720p output mode, and not having jaggies 100% of the time can actually be preferable to a tiny loss of resolution a small part of the time. If the set does handle deinterlace well, there should be no jaggies, and 1080i is probably the best choice.

No matter what your set's native rez, you would gain very little if anything by matching the Tivo output resolution to the recorded content's resolution, and in some cases doing that could actually degrade the PQ, depending upon the display (plus, constantly doing that's a total PITA). You are really better off trying both 720 and 1080 content once each at both 720 and 1080 output rez, and using what combination looks the best on your display, taking a general cue from the above, and just leaving the output set there permanently.

But there is certainly an advantage to a 1080p set in that when 1080i is processed properly during the acquisition, the 1080p progressive time relationship between adjacent lines is preserved, and is stitched back together as true 1080p, even from most 1080i sources, and then displayed as true 1080p. Also, ironically enough, SD content seems to look better on 1080p sets.

[TyroneShoes]

...While TyroneShoes will chime in and say that 1080i doesn't mean more pixels (actually, he doesn't say that, but I don't really understand the distinction he's drawing), it seems logical that, when setting the HR10 to 1080i, and using a 1080i source, you're getting to see more pixels than if you watched a 1080i source with the HR10 set to 720p... I don't disagree with that last part, Ab, but I think you might be comparing apples to oranges. The amount of visual information displayed as pixels over time is roughly the same with both 1080i and 720p, chiefly because 720p repaints the raster twice as fast as 1080i (60 frames vs. 30 frames). That's a hard fact based in the application of the physics of the ATSC standard. But that is very different than either potential resolution, actual resolution, or perceived resolution.

1080i has the potential for increased resolution over 720p by definition, for static images. It is questionable how often that potential is actually realized, however, and that potential resolution may be offset by motion artifacting in 1080i that does not affect 720p, which is what makes 1080i the format of choice for drama, and 720p the format of choice for sports and action. Perceived resolution is all that really counts in the end, and under some circumstances 1080i will have higher perceived resolution than 720p, while under other circumstances the opposite will hold true.

So, it's a very complex issue, and boiling it down to how many pixels are displayed on your screen is a gross oversimplification, so I would prefer not to have words I never uttered put in my mouth, but thank you just the same.

...you need to be close enough to your TV for your eyes to even resolve the 1080p pixels. I site about 8-9 feet from my 60" TV, which is about the right range for the size... Since 20/20 vision can resolve 1/60th of a degree of arc, if you do the math (spherical trig, actually) a seating distance of about 3 times the picture height (or closer) is needed for perceived full resolution of 1080i/p, which is what the ATSC standard used as a guideline when originally determining seating distance vs. resolution. This was based on the NHK recommendation of 3.3 picture heights for their 1125-line analog HD system from the early 80's.

Check out the viewing distance calculator for much more on this subject at www.myhometheatre.homestead.com. This determines that the optimal distance for a 60" set is actually closer to about 7.5 feet.

Now here is an application where the importance of a higher native screen resolution comes into play in a way that may even be more important than the actual, potential, or perceived resolution, and that is that at 3 picture heights the pixel structure of a 720-native set can be very visible, distractingly so, while 720p content on a 1080p set at that same distance looks better, because even though the perceived resolution is the same, the screen's pixel structure is invisible rescaled to 1080p.

The pixel structure of a 768p-native set is all but invisible, or just starting to become visible at that distance, so is better than a 720p set, but really looks best at about 8 ft. or better, while a 1080p set will still have a completely invisible pixel structure at the recommended viewing distance of 3 picture heights. One more good reason to go 1080p, and one that has little to do with the resolution of the delivered content itself.