720p or 1080i screen resolution

[marcus68]

Hi,

I've narrowed down the choices for my next TV purchase (and first flat panel) to a Panasonic or a Hitachi plasma in 42" (or 50", if I can convince the wife). I like both models in both sizes.

The Panasonic displays 720p; the Hitachi displays 1080i (unusual, but true).
The Hitachi is a couple hundred dollars cheaper.
I don't expect to have any HD broadcast TV in my area for a few years.
I can't find any reviews/details on how well either of these sets displays SD TV.
I will buy a Denon 2930 up-converting DVD player which (supposedly) puts out a decent signal up to 1080p.
I have no intention of buying a Blu-Ray or HD-DVD player anytime soon.

I've narrowed the field down to these two sets, but now I can't seem to make the final decision. Panasonic has the better reputation, but the Hitachi's '1080' is tantalizing, especially with the prospect of a beautiful picture from the Denon DVD player. They both look good in the showroom.

I guess my main question is, will there be much difference between the 720p and 1080i in regards to my viewing pleasure? What about in the different screen sizes? (My sofa is 8' from the screen.)

Anyone care to weigh in?

Thanks in advance,
Marcus

 

[avaserfi]

If you gave the actual model numbers I could look up the specs but I have a feeling both panels have a native resolution of 720p and can support 1080i since flat panels never have a native resolution that is interlaced. If this is the case both televisions will most likely have better picture quality displaying 720p images over 1080i.

 

[Adam]

If it's the Hitachi that I remember, the resolution was kinda funky on it (1024x1080). They have newer ones coming out (or maybe even out) that have a different resolution than that. I can't remember why it was categorized as 1080i, but I do remember that it was the panel - not the inputs - that put it in that category.

Have you had a chance to view those in a store? I'd say go check them out and stand or sit about 8' away from them in order to judge if you can tell a difference. There are certainly discussions (even within this forum) on whether or not people can distinguish the difference between 720 lines and 1080 lines of resolution on a 42" or 50" TV from certain distances, and people disagree. Therefore, I say go check them out for yourself and see which one you like the best.

 

[marcus68]

Thanks for the replies.

I know it's wierd Avaserfi, but this Hitachi plasma's best resolution is 1080i. Check out the first paragraph of the Key Features, just after the main description:
http://www.hitachi.us/tv/browse/plasma/plasma/42hds69.shtml

I live overseas (in Dubai) and the model numbers can be very different here. The Panasonic is TH42PV70M and the Hitachi is 42PD9500TA

To Adam, I have viewed both, but in different shops with different lighting, etc. I like both.

I have seen posts about comparing 720p to 1080p, but not to 1080i. I just wonder if the 'i' makes the comparison even more irrelevant (at 42" to 50").

And I worry about SD broadcasts being upscaled by the Hitachi. Do you think, all things being equal, that it takes a significantly better processor to scale SD to 720p than to 1080i?

Or would the 1080i serve me better if I mostly sit back to enjoy DVDs that would be played on the Denon 2930, nicely upscaled to 1080i?

Thanks again,
Marcus

 

[Adam]

Marcus,

I'll be honest - this is outside of my personal experience. I can just throw in some things that I've read.

The 720 versus 1080 argument is, from what I've read, based on human visual acuity and our ability to see details and is not dependent on progressive versus interlaced video.

I've read a lot of reviews written by people who are very happy with their 720P televisions. The only real reason that I've held out for a 1080P model is because I want to also use it as a computer monitor.

Any reason that you're not looking at a 1080P model? The 42" Panasonic 1080P should be out (or out very soon), and the 50" is already out - at least here in the States.

 

[MDS]

The Hitachi page does say 1024 x 1080i resolution but that just cannot be correct. ALL HDTVs are progressive scan. When a TV is described as 1080i that means it can accept 1080i signals at its inputs but will always deinterlace interlaced signals as well as scale to its native resolution.

The specs at the end of the manual show that some of the inputs accept 720p and 1080i while others only accept 480i and 480p. It then says the resolution is 1024 x 1080 with no mention of 'i' (as expected).

I'd avoid it anyway as 1024 x 1080 is NOT a HD resolution.

 

[Adam]

Regarding 1080i on that set, this might be helpful (I didn't search around too long):

http://reviews.cnet.com/4531-10921_7-6638050.html

Seems like it has to do with the ALiS technology of the panels.

 

[marcus68]

Thanks again for the replies.

Adam - as someone 'holding-out' for 1080p, would the Hitachi fit your bill?

Perhaps I'm new to all this, but the CNet review didn't really make sense to me. I understand that there is half the horizontal resolution, but that the pixels are split in half (and so doubling the resolution). But what does that have to do with vertical resolution and whether or not it's interlaced or progressive scan? Is this perhaps because the Hitachi is not a standard 1080p, and can't be called one, but essentially performs like one?

As for me holding out for 'prpoer' 1080p plasmas in 42", they are not available here, probably won't be for a while, and will likely be out of my budget when they do arrive (judging by the price difference between 720p and 1080p LCDs).

MDS - may I direct you to The CNet link posted by Adam. The Hitachi is not a 'proper' 1080p. And the 'split pixels' seem to make it essentially an HD resolution.

Marcus

 

[MDS]

MDS - may I direct you to The CNet link posted by Adam. The Hitachi is not a 'proper' 1080p. And the 'split pixels' seem to make it essentially an HD resolution.

First, the CNet link is about a different model than the one you linked to. Either way you are correct that it is not 'proper' 1080p.

The model in the CNet review claims 960 horizontal lines but with the pixels being half height and duplicated, thus giving the impression of being 1920 as it would be if it were a normal 1080p panel. Their ALiS processor may actually do a good job of making a good image but it is a gimmick. Why didn't they make a normal panel with a full 1080p resolution? Simple - cost savings.

To me this is no different than some of the DLP chips that use 'wobulation'. It does not contain a full 1920 x 1080 pixel array but synthesizes the extra pixels. They could take the same marketing approach as the cable companies but instead of saying 'Digital quality' they could claim 'HD quality' when in fact it is not a HD resolution.

If you like the TV go for it but I wouldn't touch it when there are better choices from companies that don't play games.

 

[Adam]

Adam - as someone 'holding-out' for 1080p, would the Hitachi fit your bill?

Marcus, no. The 1024x1080 resolution is not what I'm after. I want 1920x1080. Also, I'm leaning towards LCD instead of plasma because I'm leary of burn-in if I use it as a computer monitor for long periods of time. I've read that burn-in is less of an issue for some of the newer plasma panels, but - logical or not - I still shy away from it. I'll research it some more before I buy, though.

Personally, I'd pick the Panny out of the two sets that you listed. I didn't say it earlier because it's a personal preference, but that's the one that I'd get. I've just read so many good reviews of their plasma sets.

 

[marcus68]

Thanks guys.

I think the CNet link was suggested by Adam to explain the ALiS thingy. Sorry for any confusion. My link to Hitachi was just to illustrate that ALL the Hitachi plasmas only ever say 1080i, or "1080p input compatible". It never says Full HD for any current model.

I've just done some more research and found that the model I'm looking at does not have this 960/split pixel system. That's the system for the next generation of Hitachis. The one I'm considering is 1024x1080.

I just still don't understand about the p and i.

I understand that at 1024x1080 it's not Full HD. Is this TV simply incapable of progressively scanning at 1080? Does it 'scale-down' a 1080p signal to 1080i?

All things being equal, will 1024x1080(i) be significantly different that 1024x720(p) for a 42" or 50" at 8 feet away, and assuming an upscaled DVD 1080p feed?

 

[MDS]

Interlaced draws the even lines first and then the odd lines (like a CRT). Progressive scanning draws all the lines in sequential order.

Normal fixed pixel displays are always progressive scan regardless of their resolution. HD resolutions are 720p (1280 x 720) and 1080i/1080p (1920 x 1080). Some sets do use weird resolutions like 1366 x 768 (768p) which is slightly higer than 720p in both the horizontal and vertical dimensions but at least not way out of the ballpark like 1024 x 768 or this Hitachi at 1024 x 1080.

 

[BMXTRIX]

I just still don't understand about the p and i.

Progessive scan and interlaced scan are very difficult concepts to get, but what you need to understand is that what you FEED a plasma is different, almost always, than what it displays!

An analogy: Your TV speaks English (native resolution/language)
Your TV understands French, German, Greek, Spanish, and English (compatible resolutions/languages)

Before your TV can show the French stuff, it must first be converted from French (1080i) to English (1024x1080).

Obviously, the best translation will be if you feed the TV English to begin with!

#2: All digital displays including plasmas, LCDs, DLPs, LCoS, etc. are progressive scan. 1080p is defined as 1920x1080, typically at 60hz, so a 1024x1080 display is NOT 1080p, nor is it 1080i, it is 1024x1080 progressive scan, which can be shortened to 1024x1080p. Without the leading 1024 it is not accurate. It is also VERY inaccurate to call it 1080i or 1024x1080i.

Is this TV simply incapable of progressively scanning at 1080?

At 1080 what? You can't just say 1080, because that means nothing. This TV displays 1024x1080 in progressive scan. But, as said above, 1024x1080p is not 1080p which is 1920x1080p at 60hz.

Does it 'scale-down' a 1080p signal to 1080i?

Read on this form the languages it understands:
http://www.hitachi.us/tv/browse/plasma/pdf/42HDS69.pdf

You will see that it accepts 480i, 480p, 720p, and 1080i... It does not accept 1080p at all. So, of the languages I listed above in my example, we can call 1080p Latin - and since the TV doesn't understand Latin to begin with, it has no way to translate it to English (1024x1080p).

All things being equal, will 1024x1080(i) be significantly different that 1024x720(p) for a 42" or 50" at 8 feet away, and assuming an upscaled DVD 1080p feed?

All things being equal, then the greater resolution tends to be better.
But, since NOTHING is typically equal, and displays have vastly different video processing and build quality as well as black levels, motion handling, color accuracy, etc. it is impossible to say which of these two displays will be better.

One thing is for sure: If you use a cheap upconverting DVD player, then you might as well not buy a new display because the processing of the DVD player will screw up the movie royally to begin with. You do NOT want to upconvert DVD to 1080p unless the player is going to do a top notch job with the conversion and the display will properly work with 1080p. Many LCD displays will do this, almost no plasmas will. Very few DVD players do a good job upconverting DVD, and I'd rather spend the money on HD discs such as HD DVD or Blu-ray in a second over upconvering DVD.