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I've read conflicting things about this, and nobody seems to have a very clear answer-- what is the REAL resolution you can normally expect from a direct-view HDTV? Apparently it's known that there are some issues with masking and the vacuum tube itself limiting the resolution a direct-view tv is capable of to less than 1080, but nobody ever comments on how much actual resolution you see when you watch, say, 1080i on a direct-view set. I read one thread on the forum were someone said they'd estimated their princeton 3.0 to be putting out approximately 800 x 600 resolution (where the set's native scan rate is 768p), another guy said the same for his 34" sampo, which is supposed to scan all material in 720p. A review I read for the Loewe 38" Aconda stated that he measured 960 lines of resolution from the set. Presumably this was from a test pattern but he didn't explain his methodology at all.


How much resolution are consumer direct-view sets really capable of?


What's a good "real" resolution to expect? How much do you tend to get, for example, from most 34" models from Toshiba, Sony, etc? How much from higher-end offerings like Princeton or Loewe?


How exactly do these limitations arise?


How can you determine the "REAL" resolution of your set?



... anybody have any ideas about this?
 

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You are definitely opening up a can of worms. Actual resolution is determined by many factors. Once a monitor is properly calibrated, about the best way, IMO, to determine the display devices resolution is using a test pattern. Of course, this may be limited by the source and a static test pattern in no way represents the actual resolution of a moving image or a different type of source input other than the one in use.


My suggestion would be to not worry about this issue too much. The more you learn about resolution factors, the more you will realize how much more there is to learn.


If you really want to learn more about this subject, you will be better served by gaining your knowledge from professional standards organizations. Of course, you'll have to pay for most of their info. Check out the following links:

http://www.smpte.org
http://www.atsc.org


If you join SMPTE, you will receive a monthly journal that is worth the membership alone. Good luck in your quest.
 

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I believe you can expect a little over 800 lines of horizontal resolution from most consumer directviews (1200 on rear projectors with 7" CRTs). So, 800x1080i
 

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I think the maximum resolution you could get out of a direct view monitor would be limited by the shadow mask resolution. I seem to recall that in a review somewhere (the Perfect Vision), Gary Merson said he measured the 34" Sampo had a max resolution of around 850 lines, which was probably the maximum number of holes in the mask on a horizontal scan line.


Does anybody have a way to measure this?


Ron
 

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Panasonic specs their 34" set at 800 lines resolution (vertical lines). Nobody else gives specs. I tried measuring my Toshiba 34HF81 by putting a ruler upto the screen on the gray bars and counting the number of lines within .5" and it calculated out to just under 900 lines, but this isn't real accurate. I don't know how many horizontal lines they can do.
 

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This would be good information to have for those using their TV with an HTPC. I am planning to build one, and I'd like to match the HTPC output to the TV's actual exact resolution of my Sony KV-32XBR400. I dont care about how good or bad it makes my purchase look ... I just want reliable information so I can make best use of my purchased products.
 

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I base my opinion on what the Resolution a TV can display by using the Dot Pitch of the Tube. The distance between to pixels or dots would ultimately determine the resolution of the CRT. Of course the electronics must have the bandwidth to support the resolution, ut we'll assume that goes without saying. Anyway, let do some math (Please verify my numbers/calculations and assumptions). We'll use the RCA F38310's 38" 16x9 tube as the example. The rated dot pitch for this CRT is .78mm and with some trig I get the hight to be 21" and the width to be 31.5". Converting the .78mm to inches (25.4mm to the inch) I get a .03071" dot pitch. Now, 31.5" divided by .03071"/dot = 1026 dots available to "light up" horizontally. 21" divided by .03071"/dot = 684 dots available to "light up" vertically. So my spin is, this set has a theoretically best horizontal res of 1026 lines and a vertical res of 648 lines. Any thoughts on this?
 

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Quote:
Originally posted by jayco59
So my spin is, this set has a theoretically best horizontal res of 1026 lines and a vertical res of 648 lines. Any thoughts on this?
Welcome to the forums. Haven't tested your calculations, but your results seem close to snippets I've seen in other posts over a long time. And such results seem more than adequate for a DVD's theoretical 480X720 resolution.


How about HDTV? The committee of experts that measured ATSC resolutions for the FCC no doubt used the best gear available in the mid-1990s. A while back I converted their results to this format:
Code:
Code:
[B]Measured resolutions of the ATSC 1080iX1920 HDTV system[/B]
           
Scan format         
1080 vertical lines
1920 horizontal pixels

                                     Vertical       Horizontal        
Measured B&W Static Resolution       800            1638
Measured B&W Dynamic Resolution      400            1780^
Measured Color Static Resolution     280            890
Measured Color Dynamic Resolution    200            481


[B]Measured resolutions of the ATSC 720pX1280 HDTV system[/B]
           
Scan format         
720 vertical lines
1280 horizontal pixels
                                     Vertical       Horizontal         
Measured B&W Static Resolution       550            1139
Measured B&W Dynamic Resolution      420            1068
Measured Color Static Resolution     360            641
Measured Color Dynamic Resolution    320            605
A description of the conversion assumptions are in my 8/22/01 post here (end of thread).


So, the experts measured 800X1638 for a static B&W test pattern and 400X1780 for a dynamic B&W test pattern. I'd speculate that to see that 800X1638 resolution, the committee's test gear could display 1080 lines (540 in each of two interlaced fields). That is, their monitors didn't have the limitations in the number of horizontal scan lines (or horizontal resolution measured with pixels) that most consumer sets have. More recently, in "HDTV programs can't provide 1920 X 1080 because..." , I outlined some related factors that diminish HDTV resolution. -- John
 
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