AVS Forum banner
Status
Not open for further replies.
1 - 15 of 15 Posts

·
Registered
Joined
·
170 Posts
Discussion Starter · #1 ·
With respect to geometric alignment, what would be considered acceptable. I have a new Panny CT-32HX40 HDTV. I have had 2 service calls on it, the last one after an engineer from Japan was sent to train service techs on alignment issues. My TV still has pincushion through the center area (10" wide section) on both sides (no service menu control for this) and horizontal bowing on the upper 1/3 of the screen (the tech straightened the bottom so menus wouldn't look so distorted but the bowing moved to the top, there is no independent control available). My last TV was a B&O MX 5500 and the alignment was perfect. Please comment.


Thanks,


------------------

Tom Taylor
 

·
Registered
Joined
·
3,027 Posts
Take it back and get an HD-RPTV. The resolution on the direct views is not near HD quality.


------------------


 

·
Registered
Joined
·
772 Posts
IMHO, quality on RPTV does not compare with direct view even though it displays more of what 1080i has to offer.


This is a misconception that many get fooled by. The increased resolution does not outweigh the increased contrast/brightness of a tube in terms of overall picture quality.


The image quality of a 15" LCD flat panel running its max res of 1024x768 is better than, let's say a 19" crt running 1280x1024. Contrast ratio is much higher, and images appear crisp and not as fuzzy. Why? They are using different display technologies.


Front projection is a different story. With front projection systems set up with the correct ambience lighting, you get huge screen areas without suffering from the image quality degradation that RPTVs suffer from.


MMAfia
 

·
Registered
Joined
·
97 Posts
So are you saying direct view tvs (like rca mm series, sony xbr, princeton ar3.2) are sharper than rear projections(toshiba h80s, mitsubishi, pioneer)? IOW, that the pixels themselves are sharper?
 

·
Registered
Joined
·
98 Posts
The screen on direct view set cannot display HD resolution because the dot pitch or line pitch is too coarse. Furthermore, with a 32"-38" direct view, you would have to sit quite close (about 5 feet) to be able to see the detail in an HD image.


From 5 or 6 feet, the direct view set can give an impressive looking image with high apparent resolution because of the high contrast of the tube, but it actually displays much less real resolution than a good RPTV in the 50+" range.
 

·
Registered
Joined
·
3,027 Posts
I'll put my RPTV's contrast/brightness up against any direct view and win. Front or rear projection does not make a difference in picture quality. The difference is the quality of the projector.





[This message has been edited by Bill (edited 06-07-2001).]
 

·
Registered
Joined
·
98 Posts
I should have said apparent sharpness. Real and apparent resolution is much, much higher on good RPTVs than on direct view sets. Put a well tuned 55" or 65" inch RPTV next to a 35" direct view and you will see much more detail in the RPTV image. The 35" direct view will win in contrast and apparent sharpness because of its smaller size, but then a 19" direct view will have even more contrast and apparent sharpness.


Direct view sets do not have "sharper pixels". In fact direct view sets cannot even display single HD pixels - their resolution is so poor that they combine many HD pixels into one.


Most people have never seen a properly tuned RPTV (hint - you will never see one at an ordinary retail store like Best Buy or Circuit City) so they have no idea how good it can look.
 

·
Registered
Joined
·
221 Posts
I read an article in one of the Society for Information Display journals last year (sorry, I don't have more details, the article is in storage)that said that CRTs often look better than resolution numbers imply because of their superior MTF, modulation transfer function. From the beginning of the article this guy made it clear that, from a visual science standpoint, resolution combines with a quite a few other factors to characterize a display.


Any professionals in the field with comments or more information on MTFs?


Milton Henry
 

·
AVS Forum Special Member
Joined
·
11,139 Posts
Recently I participated in a newsgroup thread in which this SID paper was also raised in support of direct-view CRT displays for HDTV. Haven't seen it myself, but believe the researcher involved was associated with Philips' Dutch research labs. The points presented in the paper were technically very hairy and, IMO, in need of translation into easier-to-understand terms. Part of it, I recall, factored in the importance of the contribution to overall resolution made by the color signals.


Seems logical. I'm sure the paper's author must have factored in that resolution specs are usually given for black-and-white test patterns (stationary and dynamic), with color resolution given separately (see section 2.1 ). No doubt the author's contribution was scientifically impartial. But it's also useful to factor in, if it's the case here, that he may be working for a major international supplier of direct-view-CRT HDTVs. Just for disclosure purposes, I'll mention I own a high-end Philips RP HDTV, and I'm firmly in the RPTV/FPTV camp for 'serious' HDTV viewing (where there may be resolution-inhibiting projection lenses, a fresnel lens and a lenticular lens between the CRT phosphors or LCDs, etc. and your eyes, but not the severe resolution restrictions of a metal shadow mask or vertical grille. Ultrafine shadow masks in computer monitors, of course, deliver full HDTV resolutions, but such CRTs can't be engineered bright enough for reasonable group viewing, and if you sit too far from a smaller screen your eyes won't resolve finer details.) -- John


------------------

STOP DVI/HDCP AND DFAST




[This message has been edited by John Mason (edited 06-07-2001).]
 

·
Registered
Joined
·
772 Posts
RPTVs cannot generate image clarity that beats front projection systems for a number of reasons (i.e., the best well calibrated FP setup, using 9" crts will produce better image quality than the best RPTV setup using 9" crts under optimal viewing conditions).


RPTVs have to cope with being an all in one box, meaning it has to use mirrors etc. etc. to project a large surface area and still fit in a not-too-thick box, which is why calibration is so important, but it cannot COMPLETELY eliminate light signal degradation. Front projectors can be placed at the correct distance away from the screen to produce the large image area, w/o having intermediary reflections/distortions going on.


MMAfia
 

·
Registered
Joined
·
170 Posts
Discussion Starter · #12 ·
Thanks for the comments. I didn't mention that space restrictions prevent me from anything larger that the Panny CT-32HX40. This TV measures 31.9" wide and 26.5" high. I have sliding pocket doors on my Entertainment Center and they clear the TV by less than .06" per side. If my wife would let me put regular hinges on the doors, I'd get a 16 x 9 (Loewe 30" or possibly Panny 34" (but those side mounted speakers would be inside the cabinet which would cause another problem). I have viewed HD RPTV and they are beautiful. Maybe if I get a new wife, but then I won't have any money left!!! What a catch 22.


If you can comment on my original question, please do.


Thanks,


------------------

Tom Taylor
 

·
Registered
Joined
·
33,592 Posts
I must disagree with MMafia. I had, for the longest time, truly disliked RPTVs. That was until I saw a properly adjusted and calibrated HD PRTV. The appearance of a set like this can best be described the way a friend of mine (who also had no use for RPTVs) described mine when he first saw it "it looks like a 64" direct view". Aside from the greater contrast & brightness inherent in direct view tubes, a good HDRPTV totally blows away a direct view in the total viewing experience. The picture is significantly sharper and, I find the colors to be better.


Somewhere I recall reading a technical paper that explained why color accuracy is inherently better in HD RPTVs as opposed to direct views. My viewing experience would tend to support that.


NOW, as far as brightness & contrast are concerned, brighter is NOT always better. Think about your movie theater experience. The brightness on a movie theater screen MUCH MORE closely resembles the brightness of a RPTV than a direct view CRT. I am personally after the MOVIE THEATER experience. When I watch a direct view, I feel like I'm watching "TV", however when I watch my HD RPTV, I'm at the movies. Pure and simple, a much more enveloping and realistic experience.
 

·
Registered
Joined
·
772 Posts
Well, like i said, IMHO...


Don't get me wrong, HD RPTVs can look fantastic, and it does give the best 'theater' experience for the space, no doubt (although FP would be even better if you had space).


I just don't get the same 'looking through a window' effect when watching HD. Could be that all the HD RPTVs displaying HD that I've scrutinzed weren't properly calibrated, but that includes my friend's Tosh 40H80 (granted not the highest end HD RPTV set, but one of the best for its size), which sucked outta the box so he got it ISF-ed and it looks way better now, but...


here's a link to an ongoing topic in the htpc forum that's *sorta* related.. check it out:

http://www.avsforum.com/ubb/Forum12/HTML/011135.html


different strokes for different folks


MMAfia


[This message has been edited by MonkeyMafia (edited 06-07-2001).]
 

·
Registered
Joined
·
24 Posts
Theese 2 direct-vu set's should satisfy you guys;


1000 lines , dot pitch between .32mm to .36mm


Panasonic AT-H3017W 30" 16 x 9


Sony BVM-D32E1WU 32" 16 x 9


The only problem is cost. (between 25 to 30k $!!!!!!!)
 
1 - 15 of 15 Posts
Status
Not open for further replies.
Top