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DVD progressive scan OFF works better on Samsung DLP


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#1 of 16 Elias

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Posted May 27 2003 - 04:11 PM

I thought I would take a moment to describe my experience with the DVD connection to my new Samsung HLN617W DLP TV. Briefly, I recommend that the DVD player Progressive Scan feature is set to OFF for optimum viewing on the HLN series.

I bought a Panasonic RP-82 player a few months ago specifically because it was highly praised for its Progressive Scan technology, anticipating that high-quality video signals would be a must for the 61 inch Samsung DLP TV, which I received two weeks ago.

I initially connected my RP-82 to the Component 1 input on the TV (this is the DVD input that accepts 480i and 480p) and turned the RP-82 Progressive Scan feature ON, sending a 480p signal to the TV input. I noticed two problems when viewing DVD signals in this fashion. The first problem was that the image was extremely dark on the TV such that many details in dark scenes could not be discerned from the background (I refer you to the scene in the rain when Kirstin Dunst is attacked by thugs). This problem could not be significantly corrected by increasing the brightness on the DVD component video output (the RP-82 allows you to toggle between a lighter and darker picture; this setting is actually supposed to be on 'darker' when connecting to bright DLP and plasma TVs). Furthermore, even with the 'lighter' picture coming out of the DVD player, I could not correct the problem using the brightest picture mode on the DLP TV (Dynamic). The second problem is that the color of the picture was off, biasing toward green colors. This was especially apparent in The Matrix, where half the movie (all scenes taking place in the Matrix itself) is filmed in a washed out greenish/grey color. These scenes appeared abnormally green (and dark)using my DVD player's Progressive Scan output (take a look at the scene when Agent Smith first meets Neo in the office). Both problems remain unchanged when the signal is sent to the other TV inputs (Component 2 and 3).

It appears that I was not alone in noting deficiencies with this connection method. Several people on this site have voiced their opinion that the picture looks much better when the progressive scan feature is OFF on the DVD player, and a 480i signal is sent to the Samsung DLP. I was utterly surprised to hear this, since the RP-82 is so highly praised for its Progressive Scan capabilities. I also assumed that the TV would be inferior to the RP-82 in deinterlacing technology. On the contrary, the DCDi chip on the Samsung DLP TV is quite good and does better progressive scan conversion than the RP-82 chip.

I therefore went ahead and disabled the Progressive Scan on the DVD player (necessitating connection to the Component 1 input, which is the only input accepting 480i signals) and immediately noted correction of both problems. The image was much brighter, with greater detail in dark scenes, and the annoying greenish tint was gone. I did notice, however, that the background in dark scenes was on the gray side (as opposed to black). I guess DLP TVs are known for this black-level problem. I decided that I needed to bring the brightness down on either my DVD player or on my TV. I experimented with both of these methods and noticed that details were unacceptably lost with my DVD player in the 'darker' picture mode. I ultimately created a custom setting on the TV which seems to be the best compromise of detail vs. black-level in dark scenes. I will be happy to share my settings, which are similar to the 'Movie' mode with some modifications:

--Custom settings for DVD movies using 480i output
(RP-82 output set to 'lighter,' with Progressive OFF)
Contrast: 80
Brightness: 45
Sharpness: 75
Color: 60
Tint: bar is half red and half green

I hope this thread will serve not only to make people aware of this issue, but also to get others' opinions as to the optimum TV picture settings for viewing DVDs on the Samsung HLN DLP TV series. I am willing to bet that my settings can be much improved upon.

Elias Aliprandis

#2 of 16 Todd Alexander

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Posted May 28 2003 - 12:49 AM

Thanks for letting us know. I like the picture of the DLPs quite a bit. I had thought I would need a new DVD player. I have a nice, but older Toshiba non-progressive DVD player, so it looks like if/when I upgrade my TV to a DLP I won't need to spend any more $$$ on that.

Are all the inputs on the set customizable?

#3 of 16 Elias

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Posted May 28 2003 - 01:51 AM

Yes. All the inputs are customizable.

#4 of 16 Bob McElfresh

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Posted May 28 2003 - 02:28 AM

I believe that television has the Farajuda chip which works ONLY on 480i inputs. It does the scaling/de-interlacing before the DCDi chip. When you pass it a 480p signal, the Farajuda chip is bypassed.

But I'm suprised that this affects brightness/darkness of the black levels or the overall picture. There must be some interaction going on or the Farajuda chip is doing more than scaling/de-interlacing.

Congrats on the TV by the way.

#5 of 16 Elias

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Posted May 29 2003 - 01:11 AM

It seems that the TV's scaling/deinterlacing chip is designed to produce the correct colors for the TV. An interesting experiment would be to try 480i vs. 480p on another TV with the same DVD player and see if the same problem exists.

#6 of 16 Michael TLV

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Posted May 29 2003 - 01:37 AM

Greetings

480i signals are generally compromised compared to the 480p signal.

If you go the TV deinterlacing route, you also give up resolution and possibly add image artifacts too.

Regards
Michael @ The Laser Video Experience
THX Video Systems Instructor/ISF Instructor
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#7 of 16 Elias

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Posted May 29 2003 - 02:32 AM

I've compared the 480i and 480p images via the Component 1 input on the Samsung HLN617W with different scenes and found that they look identical in terms of resolution. I have not seen any image artifacts with either the 480i or 480p input.

The only difference aside from the color problem is that in dark scenes, I can see more detail with the 480i image because the progressive out of my DVD player causes dark images to be indistinguishable from the dark background.

#8 of 16 Allan Jayne

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Posted May 29 2003 - 02:37 PM

Hint: When the TV does scaling, incoming progressive scan video has to undergo an A/D conversion to get scaled while incoming interlaced video has to undergo just one A/D conversion for both de-interlacing and scaling. So the progressive DVD player's advantage is greatly diminished.

Video hints:
http://members.aol.c...ynejr/video.htm
.

#9 of 16 ManW_TheUncool

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Posted May 29 2003 - 03:49 PM

Not sure, but sounds like maybe part of the problem might have something to do w/ matching the gamma curve between player's 480p output and the TV -- check AVIA for some more on this. Maybe the TV's full deinterlacing/upconversion process is optimized for better gamma match w/ 480i inputs. I guess the Panny RP82 doesn't offer gamma control like some other players for you to tweak and test.

_Man_

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#10 of 16 Mike_A

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Posted May 30 2003 - 07:55 AM

allan - remember that when you're using component connections, the signal is analog, even if it is 480p. thus both 480i and 480p signals will have to undergo A/D conversion if the scaler needs a digital signal to scale.

and of course the advantage of a progressive scan DVD player is that it can do the deinterlacing all in the digital domain, helping to minimize the # of D/A & A/D conversions.

There's something wrong with this setup here, there's no reason that progressive should look worse. It may use diff black levels by default in progressive mode, but that's about all i can think of. properly calibrated with Avia/VE, progressive should look better because of better deinterlacing, and brightness levels should be equivalent.

#11 of 16 Elias

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Posted May 30 2003 - 09:14 AM

The interesting thing is that I am not the only one who has observed this problem. The Panny RP82 doesn't let you tweak anything. I will try to play with the settings on my TV, but so far, the 480i signal really looks much better.

#12 of 16 ManW_TheUncool

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Posted May 30 2003 - 10:01 AM

RE: deinterlacing, I don't think it's at all clear that the Panny RP82 will deinterlace better than the Sammy DLP TV, which uses the newer FLI2310 chip. Granted, you delay the D->A->D conversion til after deinterlacing when using the RP82's output, but unless we know how the FLI2310 works for format conversion(!), you can't be sure that's really better.

For all we know, the one-step format conversion from 480i->DLP native resolution might really yield better results than 480i->480p->DLP native regardless of where the D->A->D conversion occurs since it has to occur somewhere in between steps. When you do 480i->480p->DLP native, you introduce artifacts (like rounding errors in math) at each step of the process that you might not w/ the 480i->DLP native method. This is, of course, just "theory" and speculation, but it does help show that what Elias is seeing can really be what one can expect despite proper setup.

Anyway, since you cannot control gamma w/ the RP82, I'm thinking that's still a possible explanation for the lost detail in dark images. On my RP91, I find that boosting gamma can indeed help w/ the kind of thing that Elias is pointing out. Also, if you checkout AVIA's explanation about gamma, you will see why that may be so. FYI, the gamma pattern is under the special(?) section where you find the overscan and y/c delay patterns. It's something that doesn't get much press when talking about basic calibration since I guess it isn't basic at all.

_Man_

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#13 of 16 Elias

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Posted May 30 2003 - 02:27 PM

Another interesting thing is that the non-HDTV signals from my cable box are sent to the TV as 480p (the cable box gives you an option to send them as 480i or 480p), via the Component 2 input (accepts 480p, 720p, 1080i). I do not observe the dark/green problem with the cable box's 480p images. I wonder if this helps pinpoint the problem to the RP82's de-interlacing chip, and not to the TV.

Is anyone aware of any "secret" menus available on the Samsung HLN-series DLP TVs that could address this gamma issue? The only adjustable options available on the on-screen user menus are contrast, brightness, sharpness and tint.

#14 of 16 Bill_San

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Posted June 02 2003 - 08:14 AM

Elias,

My dad has an HLM series Sammy 43" DLP with a Sammy 160 HD Sat box. He has an HK 525 receiver. We wanted to hook up his existing Panny-RV36 (non-progressive scan) DVD and the HD Sat box, using video switching on the HK, to a single input on the TV.

But it would not work because the HD source must go to video input 2 on the TV but video input 2 does not support 480i input for the HLM series TV.

So I went to Best Buy and picked up a Panny RP-69 progressive scan DVD. Now both sources go through the HK and then to the TV connected to video input 2.

The difference between the progressive scan and non-progressive scan (when we had the non-progressive scan DVD hooked up to video input 1) is night and day. The progressive is much sharper as expected--it looks almost like HD, clearly the resolution is finer. There are no degrading artifacts whatsoever.

All connections are made using component video connectors.

But you say you tried video input 2 on your Sammy so I am surprised to hear of this unusual situation.

Bill

#15 of 16 andre-k

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Posted June 02 2003 - 02:55 PM

could it be because the dlp automatically converts all signals to 720?

#16 of 16 James Bergeron

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Posted June 03 2003 - 03:14 AM

Ok, just want to add, that I have the RP-91 Dvd-player and I can concure that 480p is MUCH MUCH darker than 480i. I have attempted this on a "dumb display" my NEC 6pg projector which is data grade. It doesn't know what it is getting and the interlaced image is SOOO Much brighter it is insane.

This doesn't affect me as my projector has enough adjustement room to increase the brightness for the 480p signal.

The other issue you could be encountering (as mentioned I believe) is that the DLP panel needs it's native resolution and the chip in the TV does this properly first.
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