1080i is the what HDTV usually broadcasts at (it should look just as good as 540p). ABC does broadcasts their HDTV content at 720p, but a good HDTV receiver will upconvert that to 1080i for HDTV to properly display the HDTV content on the HDTV monitor.
480p is the best that DVDs will look on a display that is capable of displaying it correctly. But HDTV content has the edge in picture quality, by at least 60 lines of vertical resolution (1080i can look like 540p).
Toshibas upconvert 480p to 540p. There's actually a small drop in overall resolution, but it's really tiny and I doubt that you'd notice it watching a movie or anything except a test pattern.
Slight drop in resolution and the addition of some interference patterns. Easily seen in test patterns ... less so in real life stuff. Still there though ...
Not if the upconversion isnt done well. The only reason they use 540p is a cost issue. Apparently the Hitachis do a much better job at the upconversion than the Toshibas do.
Is there any way to tell what resolution your TV is displaying? The new Toshibas are 720P "Capable" is there anyway to tell if you are watching ABC in 720P. My understanding is that 720P is better for Sports oriented programming than 1080i.
Michael TLV modestly fails to mention his article on the Keohi high-def site which includes screenshots of test patterns showing the loss of resolution on the upconverted Tosh in the 520-540-line (more or less) range. Here it is.
As you'll read in the article, hardly any DVDs attain this measure of sharpness.
The only thing missing is a comparison with Hitachi upconversion (hint, Michael, hint). Given how minor the effect is with the new Toshibas, I don't see how the Hitachi upconversion could be "much" better, but I'd like to know exactly what we're talking about.
Here's the thing that concerns me about the whole upconversion conversation: Yes, the effect is real, but it's also really, really minor in the face of other factors. I think the Toshibas have the best color fidelity OOTB, for instance, are free from red or blue push, it's easy to tweak the color or adjust the geometry in the service menu, marginal signals are dealt with very well, the internal line doubler is excellent, the form factor is very shallow, etc.
Yet, I still see posts that say, "Toshiba is out of the running because it upconverts the image," as if this were a major flaw. All else being equal, then upconversion could be the deciding factor; but all else is never equal.
All sets have their trade-offs. I can see people preferring another brand over Toshiba...and I don't work for or own stock in the company ...but it pains me to see people missing out on a good set or a good deal because upconversion has taken on Godzilla proportions in their minds.
Which is why Michael's article is so good. It shows you the problem, how big it is and how big it isn't, so you can give it the appropriate weight in your buying decision.
Doug Smith: 540p would be better than 480p if the source were 540p. However, upconverting from 480p to 540p just spreads the same image over more lines and doesn't really add any resolution.
Jan
FWIW, I have also seen claims by HTPC folks that a top quality scaler (like in HTPCs) combined w/ a TV optimized for 1080i (read at expense of 480i/p) will produce 540p viewing that's better (read more "film-like") than 480p into an HDTV that does not upconvert. Yes, seems that many (or all?) HDTVs can accept a 540p signal. The idea is that optimizing for 1080i/540p alone will provide better convergence that more than offsets the inevitable resolution loss in upconversion.
BTW, in the few claims I've seen, IIRC, these people all used displays that would force upconversion, if the source is not already 540p or some other native resolution, so I would take that w/ a grain of salt.
BUT as both Jan and Mike pointed out, the resolution loss of the Toshiba is slight. You might never notice it if you don't look for it. And really, you're not gonna be doing A/B comparisons in your own home, will you? Also, I'd think it's less of an issue than DVD anamorphic downconversion for 4x3 TV's that don't do the 16x9 squeeze. If that downconversion never bothered you, there's good likelihood that this upconversion won't bother you either.
For myself, I decided against the Toshiba for more reasons than just the upconversion issue. Budget was a bigger factor in my case.
_Man_
The problem with Toshiba isn't picture quality or slight resolution loss from upconversion. The problem with Toshiba is a lousy and unresponsive service department. There are several issues that have cropped up in Toshiba RPTVs, such as flashing green and red guns on power up and power down, vertical ghost lines and some kind of edge enhancement that can not be eliminated by disabling SVM. Toshiba has not done anything to address the issues; other than to just ignore anybody that complains about the various problems. I even had one rep state that a flashing green gun on power down is normal operation. I sure didn't see a "normal operation" like that when I first purchased the set. If I had seen that kind of operation, I would have never bought the set. If I had known that Toshibas quality of service was going to be so pathetically poor, I would not have bought one of their sets.
Well they certainly have done nothing about the vertical ghost lines in three straight model years. Wonder why that is? ------------------------------------------------------------ Toshiba has been denying that the ghost line problem even exists. If the problem was suddenly corrected in their newer model sets, it would amount to an admission that they have been selling defective sets for three years. Can you imagine the expenses they would incur if they had to recall three years worth of television sets; the cost would be enormous. Toshiba corp. has decided the cheapest route is to deny that the problem exists. Toshiba would rather risk destroying its customer base than take the immediate short term financial hit that would result if these sets were recalled. ------------------------------------------------------------
What's a vertical ghost line? ------------------------------------------------------------
A lot of owners have complained about a faint vertical line (approx. 1 inch wide) that runs down the centre of the screen. The line is slightly lighter than the rest of the surrounding screen and is, apparently, most noticeable with fast panning shots across a very light background. Hockey games, apparently, highlight the problem because of the high speed pans and the white background caused by the ice surface. Fortunately, I have not noticed if the problem exists in my set, but then again I do not watch sports programs.
Anyway, considering the thread is about whether progressive scan improves picture quality on Toshiba TVs, I guess I should not have hijacked the thread to complain about the other problems their sets are suffering from. I apologize for doing so. I just feel that if anyone is contemplating purchasing a set, they should factor Toshiba's lousy service into any buying decision, since that is an even bigger problem than the resolution lost due to a poor upconversion routine.
I've had problems like Edwin S's with Philips and Sony. The question is: Does any mass manufacturer have excellent product support? It's a good thing to be concerned about, but I'm so jaded as to not expect it from anyone. If there's an exception out there, it could sure influence my next buying decision.