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Discussion Starter · #1 ·
(hard for me to find answers with forum searches as the keywords are too generic).


I've just bought my first Blueray a few days ago (Sony BDPS350) and hooked it up via HDMI to my (Sony KP-57WS520 57" Hi-Scan 1080i HD-Ready) rear projection CRT. We generally sit approx 15-17ft away, and the room is quite dark.


The blueray can output in any video mode 480p/i, 720p, 1080p/i. The TV can accept all but 1080p.


We can see very little difference between watching a blueray movie outputted at (480i or 480p) vs (720p or 1080i). I don't understand why/how not. They are both quite "clear" and "Sharp" but it's double the resolution and I would think I should see a notable difference.


1) Why such a subtle difference between watching BR at 480 vs 720/1080?

2) Is there a PQ difference between watching a BR at 480 vs a DVD at 480?

3) Am I missing something?


Yes the blueray verifies on screen what resolution it is pumping out and I can put the TV into programming mode to confirm when I am seeing 480 and 1080 etc. I've tried BR movies "The last Samuari", "Street Kings", and "300". I've also tried upconverting Spiderman 3 DVD and again not much difference.


P.S. I spent 4h last night cleaning the dust of the tubes/guns and tuning the convergance at each video mode/resolution (using the remote and on screen convergence tool). Retested a blueray and same results.


Thanks for any replies.


-Deuce-
 

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I would say there are a few reasons as to why you aren't seeing a difference. Major factor is how far you sit from the screen. The farther you sit away the less detail you can see. At a Bar, a 25in TV tube can look like HD from far away, but as you get closer it looks like crap. Same goes if you stick your nose on the screen you can see each pixel. As you go back to your couch you don't see each pixel. I sit 16ft from an 110in 720p projector.


One other factor is that your TV is 1080i. It doesn't matter what you throw at it (480i/p, 720p, or 1080i)... what your eyes will always see is 1080i. Your TV has a scaler in it that changes the source (bluray or DVD or CableTV) to its Native resolution. You may not see any difference because the Bluray is has a resolution of 1080p, you set it to 480P, and you TV bumps it back up to 1080i. Now yes you will loose some quality doing this but you are sitting so far away that your eyes can't see the difference. You didn't mention if you were using HDMI/DVI cables or Component, but if you are using analog, most likely you are loosing some sharpness from the Digital to analog and then analog to Digital conversion to the point you can't see the artifacts being created from all that resolution scaling.


Best thing to do is set the player to 1080i, use a digital cable DVI/HDMI, and be done with it. Yeah you may not notice anything from where you are sitting, but if anyone is closer... they will. Also, you might want to get a Bluray calibration disk to make sure it's all good. Calibrating a TV will make way more of an impact on picture quality than resolution does. IMHO
 

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Historically Sony CRT's (although I don't know if it applies to RP CRTs) dubbed Hi-scan have an effective resolution of 853 x 1080i. This could explain why you're not seeing a huge difference between 720x480p and 853 x 1080i(540p if you want to look at it that way for the total height for 1 field of the interlaced signal).


You should be able to see some though since I also had a hi-scan tube and I could tell at 34", but a full 1920x1080p will outclass it hands down.


Blu-ray at 480 should still be better than dvd due to more efficient video compression and an expanded color space.
 

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Another possibility is that you're using a CRT projection TV, which are more forgiving on lower resolution pictures (vs LCD/Plasma), but are less "sharp" at higher resolutions due to the image being a projection rather than displayed directly on the screen with each pixel having a defined space.


That's just a shot in the dark however, so don't take it as gospel.
 

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I have the 51ws520 your t.v.'s baby brother and I have to admit I haven't watched standard 480p material on that t.v. for a long time. All DVDs were upscaled to 1080i via the Zenith DVD 318, Toshiba HD-DVD A30, then finally the Magnavox BD player. But I was able to see the difference between upscaled movies and their HD counterparts, Transformers, 300 etc.


It could be a simple calibration issue here, did you ever calibrated the t.v. using a disc like Avia or anything like that. Sometime sharpness can be high as well as the contrast and I find if those settings are high, they create video noise and that could be what you are seeing therefore not seeing much of a difference.


They have HD calibration discs so you can calibrate the t.v. for high def and with the ability to have everything scaled to 1080i it should look pretty good all the way around.
 

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Discussion Starter · #8 ·
No, never professionally calibrated. I did color/contrast settings with the AVIA DVD upscaled with the blueray player. Only real change was the sharpness which I had to turn down a bit. And overscan adjustment.


Just spoke with prof calibrator and it's still quite costly. I have 5 year extended warranty with FS so I think I'll see if they will send tech to do basic electostatic and mechanical focusing. It shouldn't take him long and a little improvement could go a long way. Worth a try I guess.


Today I compared Dark Knight a bit. A 720p source blueray displayed at 1080i (via Sony blueray) vs DVD9 at 480p (via Pioneer DV-588A). And I probably saw the most difference of my comparisons yet. Unfortunatly the DVD9 will not play in the blueray for some reason (home made) so I can't compare the upscaled DVD9 vs blueray on the same machine.


But a lot of the difference was more detail in the dark areas of the scene as well as some quality/resolution. Which fits into the color talk on the 480vs1080 discussion someone posted a link to a few messages above this one.


So while I don't see a large difference between 480i blueray and 1080 blueray, I might still be seeing a noticeable (though not breathtaking) improvement in blueray vs DVD (just can't do a 100% fair comparison yet as I need a DVD and blueray of the same movie to play on the same machine)


P.S. Damn I estimate good. Took out the tape and the couch is 16ft from TV.


-Deuce-
 

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Discussion Starter · #9 ·

Quote:
Originally Posted by aliasfox /forum/post/15441176


Another possibility is that you're using a CRT projection TV, which are more forgiving on lower resolution pictures (vs LCD/Plasma), but are less "sharp" at higher resolutions due to the image being a projection rather than displayed directly on the screen with each pixel having a defined space.

Yeah this is/was my initial thought as well (my CRT might look better than a LCD at 480, but vise versa at 1080).


Hopefully some internal converging/focusing will help even more and if not, well the picture is still very good.


-Deuce-
 

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Quote:
Originally Posted by d0000h /forum/post/15439382


(hard for me to find answers with forum searches as the keywords are too generic).


I've just bought my first Blueray a few days ago (Sony BDPS350) and hooked it up via HDMI to my (Sony KP-57WS520 57" Hi-Scan 1080i HD-Ready) rear projection CRT. We generally sit approx 15-17ft away, and the room is quite dark.


We can see very little difference between watching a blueray movie outputted at (480i or 480p) vs (720p or 1080i). I don't understand why/how not.

At 17 feet people with perfect vision can't visually resolve more than 840x472 pixels on a screen that small. Horizontal detail might be a little sharper. Scenes with motion will suffer less loss of background detail because the bit rate is higher.


Moving to a more reasonable viewing distance (under 7') or getting a screen sized for your current seating distance (something in the 140" diagonal range) would help.

Quote:
2) Is there a PQ difference between watching a BR at 480 vs a DVD at 480?

Perhaps on moving material.


Also note that the CRT tube size, focus mechanism, and electronics bandwidth are going to limit the resolution you can get out of your current TV. Maxing out around 720p resolution wouldn't be out of the question.
 

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Quote:
Originally Posted by d0000h /forum/post/15439382


(hard for me to find answers with forum searches as the keywords are too generic).


I've just bought my first Blueray a few days ago (Sony BDPS350) and hooked it up via HDMI to my (Sony KP-57WS520 57" Hi-Scan 1080i HD-Ready) rear projection CRT. We generally sit approx 15-17ft away, and the room is quite dark.


The blueray can output in any video mode 480p/i, 720p, 1080p/i. The TV can accept all but 1080p.


We can see very little difference between watching a blueray movie outputted at (480i or 480p) vs (720p or 1080i). I don't understand why/how not. They are both quite "clear" and "Sharp" but it's double the resolution and I would think I should see a notable difference.


1) Why such a subtle difference between watching BR at 480 vs 720/1080?

2) Is there a PQ difference between watching a BR at 480 vs a DVD at 480?

3) Am I missing something?


Yes the blueray verifies on screen what resolution it is pumping out and I can put the TV into programming mode to confirm when I am seeing 480 and 1080 etc. I've tried BR movies "The last Samuari", "Street Kings", and "300". I've also tried upconverting Spiderman 3 DVD and again not much difference.


P.S. I spent 4h last night cleaning the dust of the tubes/guns and tuning the convergance at each video mode/resolution (using the remote and on screen convergence tool). Retested a blueray and same results.


Thanks for any replies.


-Deuce-

Get a real HDTV and you will see the diff, out with the old in with the new..
 

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If you can track down that hdnet test pattern image (might still be downloadable in a topic somewhere on this forum), it might be worthwhile to shoot that through your projector just to see what line spec it works out to.


Unlike a fixed-pixel panel display, an analog style crt doesn't have a "distinct" output resolution. It has a high-frequency response which should be fairly flat to a certain frequency and then becoming progressively weaker above that. It is possible that, while it is technically capable of casting high-frequencies corresponding to the 1080p realm, the output is relatively weak at that point (alternating black and white lines would appear gray with a subtle indication that they are actually distinct lines). The output may be at a strong reference level corresponding to a resolution of 600-700 with attenuating response above that (just picking numbers, here, to illustrate the point).


While that in of itself may not be a terminal bottleneck to getting reasonable "1080p performance", you have to account for the HF signature of film-based movies. They have their own HF attenuation (it's the difference between razor sharp as a tack sort of rendition that you get from hd-video vs. a more gentle, "smooth" appearance of film). So when you add that to the response of your projector, the result may yield a perceptually premature HF roll-off point (compared to what you would expect from your projector based on the technical specs cited for it). So that may not yield that much difference between an upscaled dvd at 480p with a touch of sharpening and full 1080p shooting through whatever the effective low-pass response is characteristic for your projector.


I included a sample of the picture I refer to earlier as an attachment. DON'T USE THIS ONE TO TEST YOUR PROJECTOR. The forum imposes a file size and resolution limit to the attachments, so it will naturally get reduced to a size/quality that would not be appropriate for test purposes. You have to find the original jpg. It will be a standard 1920x1080 resolution, just over 600 KB.




(reduced sample of the jpg I refer to...it is no longer 1920x1080 shown here, despite the name of the file)
 

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Quote:
Originally Posted by d0000h /forum/post/15439382


(hard for me to find answers with forum searches as the keywords are too generic).


I've just bought my first Blueray a few days ago (Sony BDPS350) and hooked it up via HDMI to my (Sony KP-57WS520 57" Hi-Scan 1080i HD-Ready) rear projection CRT. We generally sit approx 15-17ft away, and the room is quite dark.


The blueray can output in any video mode 480p/i, 720p, 1080p/i. The TV can accept all but 1080p.


We can see very little difference between watching a blueray movie outputted at (480i or 480p) vs (720p or 1080i). I don't understand why/how not. They are both quite "clear" and "Sharp" but it's double the resolution and I would think I should see a notable difference.




-Deuce-

Here is a recommended distance viewing chart for you.

For Smaller Screen Owners - Recommended Viewing Distance Relating to Your Screen Size
Screen Size >>>>>>>>720p >>>>>>>>> 1080p


32 inches >>>>>>>>> 6 feet >>>>>>>> 4 feet


37 inches >>>>>>>>> 7 feet >>>>>>>> 5 feet


40 inches >>>>>>>>> 8 feet >>>>>>>> 5 feet


42 inches >>>>>>>>> 8 feet >>>>>>>> 5.5 feet


46 inches >>>>>>>>> 9 feet >>>>>>>> 6 feet


50 inches >>>>>>>> 10 feet >>>>>>>> 6.5 feet


52 inches >>>>>>>> 10 feet >>>>>>>> 7 feet


65 inches >>>>>>>> 13 feet >>>>>>>> 8.5 feet



It's taken from the thread in my signature link but basically you are sitting way too far away from your screen to get any benefits from high definition.


Try sitting 8 feet away from the screen instead.
 
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