I just bought a Panasonic TH-50PZ750U. I have a vague technical understanding of why a 1080p set without 1080p/24 capability won't show a true 1080p image. Really the best I'll get is 1080i out of an HD-DVD or Blu-Ray disc, as I currently understand it. I guess this has to do with the refresh rate not being divisible by 24.

My question is, will a good quality scaler allow circumvent this issue, or will the net result of a 1080p/24 master still be 1080i for me?

I see by a general perusing of this forum that there are some great technical minds here. This leads me to believe my question is being skipped over for the sheer, painfully simplistic nature of the question, in relation to the knowledge level. So I'll dutifully study some other threads here, but if in the meantime someone answers my question, I won't be offended.

ok, i'll bite...

first off, there are VERY few displays that do 1080p/24, so if your assumption was true, not too many people would be getting 1080p, period... ;) many will accept it, but that doesn't mean they will display it...

no, you can't make it do 1080p/24 if it won't display it... this has nothing to do with scaling (scaling is a whole different thing)... the "24" part is referencing framerate... film is based on a 24hz framerate....

but that doesn't mean you won't display 1080p... it just means that you will display 1080p/60... when you are getting input from a film based source, you'll get 1080p/60, with either the player or the display performing what is referred to as 3:2 pulldown to create 60hz display from 24hz source...

if that doesn't make any sense, start by researching "interlaced", "progressive", "frame rate", "telecine", "inverse telecine" and then piece it together... :) we've all had to do it... and most of us (myself definitely included) still bollix it up every now and then... :D

ok, i'll bite...

first off, there are VERY few displays that do 1080p/24,



Could you list a few displays that can do 1080p/24? Thx

JVC rs1 and rs2, Sony vw60, vw200. Some Pioneer plasmas. Some Samsung tvs.

Just a few I can think of.

JVC rs1 and rs2, Sony vw60, vw200. Some Pioneer plasmas. Some Samsung tvs.

Just a few I can think of.

The confusion on what displays are doing true 1080/24 was one of the reasons I ended up ignoring it and going with what I know. I'm not as noob as the original post might imply; I grasp color space, scaling, 3:2 pulldown and other such basics, but for some reason I seem to glaze over on most descriptions of 1080/24. The other day a friend of mine implied that a 1080p set, because of some math, actually shows a 1080/24 mastered HDDVD at 1080i. I assumed this had something to do with the lack of 1080/24 support, but I could be wrong. Then again, my friend might simply be misinformed.

your friend is misinformed... digital displays can't display interlaced signals.... your display will ALWAYS display 1080p...

your friend is misinformed... digital displays can't display interlaced signals.... your display will ALWAYS display 1080p...

That makes sense, actually. So, what is the gain from 1080p/24 support, exactly? I'll continue to dig, but yeah, the explanations I've found are either not cohesive enough, or assume to much engineering/math background, IMO.

When a Blue Ray or HDDVD HD player does not output 1080p@24, it will output 1080i and perhaps a few other choices instead. The TV must de-interlace incoming 1080i which it may or may not do well and may or may not employ inverse telecine to accomplish. Incoming 1080p@24, if accepted, does not require de-interlacing and also does transmit the maximum picture detail from a film source.

Note that almost all U.S. HDTV's actually put 60 fps or (less commonly) 72 fps on the screen. While it is much easier to get incoming 1080p@24 compared with 1080i onto a 1080p@60 display with minimal artifacts, the full benefits of 1080p@24 are better realized on a 1080p@72 display. No TV's put 24 fps on the screen. A few can put 48 fps on the screen which offers some advantages over 60 fps on the screen for 24 fps source but also has a big disadvantage, more flicker.

By the way, live video sourced programs must be de-interlaced by the player prior to going out as 1080p@24. If forced onto 1080p@24 without good de-interlacing, the result on the screen will never be good no matter what the TV does.

A good scaler in between will take the 1080i from the player and make results that rival 1080p@24 but already formatted (temporally scaled) to match the screen rate of 60 or 72 fps. But the scaler is useless if the TV does not accept this 1080p input.

As far as "putting 1080i directly onto a non-CRT display" goes, extremely crude de-interlacing might consist of taking each field (half picture) and putting each scan line on the screen twice.

Video hints: http://members.aol.com/ajaynejr/viddoubl.htm

When a Blue Ray or HDDVD HD player does not output 1080p@24, it will output 1080i and perhaps a few other choices instead. The TV must de-interlace incoming 1080i which it may or may not do well and may or may not employ inverse telecine to accomplish. Incoming 1080p@24, if accepted, does not require de-interlacing and also does transmit the maximum picture detail from a film source.

Note that almost all U.S. HDTV's actually put 60 fps or (less commonly) 72 fps on the screen. While it is much easier to get incoming 1080p@24 compared with 1080i onto a 1080p@60 display with minimal artifacts, the full benefits of 1080p@24 are better realized on a 1080p@72 display. No TV's put 24 fps on the screen. A few can put 48 fps on the screen which offers some advantages over 60 fps on the screen for 24 fps source but also has a big disadvantage, more flicker.

By the way, live video sourced programs must be de-interlaced by the player prior to going out as 1080p@24. If forced onto 1080p@24 without good de-interlacing, the result on the screen will never be good no matter what the TV does.

A good scaler in between will take the 1080i from the player and make results that rival 1080p@24 but already formatted (temporally scaled) to match the screen rate of 60 or 72 fps. But the scaler is useless if the TV does not accept this 1080p input.

As far as "putting 1080i directly onto a non-CRT display" goes, extremely crude de-interlacing might consist of taking each field (half picture) and putting each scan line on the screen twice.

Video hints: http://members.aol.com/ajaynejr/viddoubl.htm

Thank you Allan. Between my own further research and such answers as yours, I've got a grasp on it. I see that I was embarassingly far-off on my original question, but sometimes you have a risk a stupid question on the internet ;)

For video sourced HD-DVD/Blu-Ray played on your average mainstream player with 1080p/24 support (for example, the Toshiba A2 HD player), it sounds like it might be a good practice to disable 1080/24 (if you can) support when playing these. I wonder if there are any players out there that allow a manual override to 1080p/60 or 1080p/24.

Thank you Allan. Between my own further research and such answers as yours, I've got a grasp on it. I see that I was embarassingly far-off on my original question, but sometimes you have a risk a stupid question on the internet ;)

For video sourced HD-DVD/Blu-Ray played on your average mainstream player with 1080p/24 support (for example, the Toshiba A2 HD player), it sounds like it might be a good practice to disable 1080/24 (if you can) support when playing these. I wonder if there are any players out there that allow a manual override to 1080p/60 or 1080p/24.

well, the a2 doesn't have 1080p/24 support... ;)

however, both my players (a20 and bdp-s1) have menu settings for resolution output... i would think that they all do, but i've thought logical things before and been wrong... :)

well, the a2 doesn't have 1080p/24 support... ;)

however, both my players (a20 and bdp-s1) have menu settings for resolution output... i would think that they all do, but i've thought logical things before and been wrong... :)

The newest firmware update adds 24 support to the A2(or so I've read here), although a few bugs have been reported with it.

Resolution settings are one thing, but distinguishing between 1080p/24 and 1080p/60 output is another. I wouldn't expect to see that granularity of control on a mainstream product, but it would be a pleasant surprise.

The max resolution of teh A2 is 1080i. the firmware update enabled 1080P24 output to the A20 and XA2. I run my XA2 through my VP50 which outputs 1080P60 to my TV. I can send 1080i, 1080P24, and 1080P 60 from my XA2 and the VP50 does such a good job that tehy all look the same. For instance there are no moire patterns from the Vatican scen on MI3 when the XA2 outputs any of those resolutions.

The newest firmware update adds 24 support to the A2(or so I've read here), although a few bugs have been reported with it.

Resolution settings are one thing, but distinguishing between 1080p/24 and 1080p/60 output is another. I wouldn't expect to see that granularity of control on a mainstream product, but it would be a pleasant surprise.

no. it doesn't. the firmware update adds 1080p/24 to the a20 and xa2 (the players that support 1080p to begin with). the a2 only supports up to 1080i. the 24hz support for the xa2 has a bug in that it sends "exactly" 24fps, vs. 23.xxx fps. it works fine on the a20.

the a20 (for example), allows you to set either "up to 1080p" or "up to 1080p/24" (in addition to other options). so you can be pleasantly surprised.

no. it doesn't. the firmware update adds 1080p/24 to the a20 and xa2 (the players that support 1080p to begin with). the a2 only supports up to 1080i. the 24hz support for the xa2 has a bug in that it sends "exactly" 24fps, vs. 23.xxx fps. it works fine on the a20.

the a20 (for example), allows you to set either "up to 1080p" or "up to 1080p/24" (in addition to other options). so you can be pleasantly surprised.

Ah. Yes, I confused the A2 and A20. That is a pleasant surprise, although somewhat moot for me since my TV is 60hz.

Ah, knowledge. I keep telling myself that with so much to know about display technology, perhaps it might be better to remain "blissfully ignorant". But that's just not my nature. My worst fear is that, having made most of my major purchases, I'll find out too much and suffer from buyer's remorse!

The max resolution of teh A2 is 1080i. the firmware update enabled 1080P24 output to the A20 and XA2. I run my XA2 through my VP50 which outputs 1080P60 to my TV. I can send 1080i, 1080P24, and 1080P 60 from my XA2 and the VP50 does such a good job that tehy all look the same. For instance there are no moire patterns from the Vatican scen on MI3 when the XA2 outputs any of those resolutions.

So in your scenario (assuming your TV does not support 1080p/24), would there be any reason to send 1080p/24 to your scaler and let it do the deinterlacing? Tell me if my line of thinking is correct here:

(Assuming no 1080p/24 support on a given TV) since the HD DVD is mastered is 1080p/24, then would it make sense to enable 1080p/24 output on the player, letting the scaler do the deinterlacing to 1080p/60? Or would it make more sense to simply disable 1080p/24 output and let the player output 1080p/60? In the latter solution, would the player then do the deinterlacing back to 60?