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How To Assess Picture And Sound Quality


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#1 alanh

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Posted 14 June 2009 - 09:44 PM

All,
Digital Video Essentials.

All of the following tests and setups come with a demonstration and descriptions of how to use them.

This disc tells you how to set up a viewing enviroment

This is the only disc I know of which enables the viewer to adjust the brightness and contrast for the lighting conditions you are actually using.

Note: In an effort to reduce power consumption in LCD displays the brightness of the display is controlled by the lighting conditions Description of the ECO system

Test the geometry and size of the image

Image sharpness test

Tests the sound system for frequency response, balance for stereo and 5.1 systems, identifing if all channels are equal and are identified as well as a rattle test. Subwooffer phase test.

With the use of a supplied optical colour filter, thest the matrix which separates the signals from the Y, Pr & Pb signals back to the Red, Green & blue signals for display. This is to ensure that the colour of strong colours are correct.

A test of how how well the processing in the display, scaler and Blu-ray player work.

The relative timing of sound and picture which is adjustable in some Home Theater Amplifiers.


Demonstration of the highest quality images from NASA and in a restaurant so you can see how good a display is on real pictures!

The advantage of these disks is that you know that they have gone to extreme efforts to make the highest quality pictures and sound.


There is Blu-Ray(HD) DVD-PAL (SD) versions available

Google "Digital Video Essentials" and restrict the search to Australia to find out where you can get it and how much it will cost.

When you buy a display the cost of this disc is around 2 % of the cost of the display. It is worth it to get the best pictures and sound.

AlanH

#2 bluebella

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Posted 14 June 2009 - 09:54 PM

Alan,

I recently bought this brand new and sealed from ebay for $33. The seller had a 'make an offer' option. I've seen it in JB HiFi and Kmart around the $37 - $40 mark. I haven't had the opportunity to use it yet (still waiting on delivery of my new plasma) but I'm happy to learn this will be a great investment for my new toy! Now, I just hope it's easy to use too!

#3 sschen

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Posted 14 June 2009 - 10:28 PM

All,
Digital Video Essentials.

All of the following tests and setups come with a demonstration and descriptions of how to use them.

This disc tells you how to set up a viewing enviroment

This is the only disc I know of which enables the viewer to adjust the brightness and contrast for the lighting conditions you are actually using.

Test the geometry and size of the image

Image sharpness test

Tests the sound system for frequency response, balance for stereo and 5.1 systems, identifing if all channels are equal and are identified as well as a rattle test. Subwooffer phase test.

With the use of a supplied optical colour filter, thest the matrix which separates the signals from the Y, Pr & Pb signals back to the Red, Green & blue signals for display. This is to ensure that the colour of strong colours are correct.

A test of how how well the processing in the display, scaler and Blu-ray player work.

The relative timing of sound and picture which is adjustable in some Home Theater Amplifiers.


Demonstration of the highest quality images from NASA and in a restaurant so you can see how good a display is on real pictures!

The advantage of these disks is that you know that they have gone to extreme efforts to make the highest quality pictures and sound.


There is Blu-Ray(HD) DVD-PAL (SD) versions available

Google "Digital Video Essentials" and restrict the search to Australia to find out where you can get it and how much it will cost.

When you buy a display the cost of this disc is around 2 % of the cost of the display. It is worth it to get the best pictures and sound.

AlanH


There is a HD-DVD/DVD (combo) version of this disk as well. Certainly well worth the investment.

I ordered multiple copies of this in blu-ray format as I thought others here may be interested as well. I should have them sometime next week. If you are after a copy, send me a PM

#4 alanh

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Posted 14 June 2009 - 10:48 PM

sschen,
I did not recommend the HD DVD/DVD version because HD-DVD is dead and the disc is double sided one of each HD DVD on one and SD DVD on the other.

The DVD-PAL and DVD-NTSC are both recorded as an SD component signal. The only differences are the frame rate, the regional coding and possibly different colour matrix values.

AlanH

#5 DrP

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Posted 15 June 2009 - 06:26 AM

Different colour matrix values is of no concern.


Incidentally, after years and years of people referencing DVE in many many threads on this forum why do you think you need to start a thread about it? Have you just discovered DVE yourself?

Edited by DrP, 15 June 2009 - 06:41 AM.


#6 alanh

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Posted 15 June 2009 - 10:30 AM

DrP,
I know that DVE has been referred to for years but I want it to be pinned.

Matrix values are important if you want the right strong colours. If you have the wrong matrix it causes the hue of these colours to change hue particularly strong greens. The other point you are ignoring is you have not seen the original scene colours.

On HD the matrix values are identical around the world but are not the same as the pair of SD standards.

AlanH

#7 DrP

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Posted 15 June 2009 - 10:31 AM

Tell me alanh, how exactly does an end user of a DVD (or a HD format) player end up using the wrong colour matrix?

The other point you are ignoring is you have not seen the original scene colours.

In order for a point to be ignored it has to be presented first. Please indicate where, in this thread, the point you are claiming I am ignoring was presented.

Edited by DrP, 15 June 2009 - 10:33 AM.


#8 DrP

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Posted 15 June 2009 - 12:36 PM

Hmm. It seems that alanh is unable to reply to my post so I'll reply for him.

The answer is, the end user can't. The colorimetry is handled entirely within the player, by the player. I have not come across a single consumer player that allows one to select the matrix used, let alone select an incorrect one. The colour matrix is determined from information encoded within the video stream.

Or to put it another way, for the purposes of the discussion of the topic of this thread, colour matrices are of no concern..... now where have I heard that before. :rolleyes:

#9 Mr.Bitey

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Posted 15 June 2009 - 01:14 PM

:is furious:

:has just spent 30 minutes typing and IE (**** i hate IE) timed out, and going 'back' shows nothing:

...

Crux of the post:

DVE only lets you set colour saturation (using the filters) that is, if your able to understand the narrative.

All THX DVDs include a THX optimiser that'll let you get about 80% as good as DVE on its own (without a SPL meter).

If you want to set the audio channel trims properly, you need a SPL meter +$50

Even then, using DVE to set the picture, will only get you at best about 40% as good as using a colour-meter - which will let you set the colour of grey (giving you a really nice picture), which are readily available second hand for ~$100 (and not that much more new).. and will let you set ALL your TV's / Displays properly (given youve got access to a laptop) - and let you calibrate your laptop screen, and any other computer screens.... then you can on-sell it for abotu the same $..

Cheers,
Bitey

#10 DrP

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Posted 15 June 2009 - 01:16 PM

:has just spent 30 minutes typing and IE (**** i hate IE) timed out, and going 'back' shows nothing:

Let me guess, white van internet services? :lol:

#11 Mr.Bitey

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Posted 15 June 2009 - 01:35 PM

Errr.... no.. no... this was Beige Truck Internet Services..... not related..

Cheers,
Beigey

#12 Karma

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Posted 18 June 2009 - 11:46 PM

So whats the general consensus? :huh:

Is it worth getting one of these or similar DVD's or further having someone come out to calibrate your panel for you?

Just midly curious as have just passed the "wear" in period on my first plasma and whilst i'm reasonably happy with the pic i've got up i'm just wondering how much better it could actually be. :D

Edited by Karma, 18 June 2009 - 11:48 PM.


#13 laurie

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Posted 19 June 2009 - 12:40 AM

So whats the general consensus? :huh:

Is it worth getting one of these or similar DVD's or further having someone come out to calibrate your panel for you?

Just midly curious as have just passed the "wear" in period on my first plasma and whilst i'm reasonably happy with the pic i've got up i'm just wondering how much better it could actually be. :D


This disc only calibrates the display there is another important factor that needs to be calibrated,and that's the inputs, in my case
1.Blu-Ray
2.IQ2 Foxtel
3.HD-DVD

STB for those without in built tuner

cheers laurie

#14 alanh

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Posted 19 June 2009 - 01:25 AM

Laurie,
You use the disc and meters if you wish to calibrate the display.
You do not need to calibrate any of the inputs provided you use HDMI inputs because the decompressed data is unaltered in STBs, players of all types and PVRs of all types.
The only exception is where you record from an analog source such as a camera or an analog videocassette. These adjustments should be performed prior to recording.
The same approach also applies to sound.

AlanH

#15 :)

:)

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Posted 19 June 2009 - 02:28 AM

:is furious:

:has just spent 30 minutes typing and IE (**** i hate IE) timed out, and going 'back' shows nothing:

...

Crux of the post:

DVE only lets you set colour saturation (using the filters) that is, if your able to understand the narrative.

All THX DVDs include a THX optimiser that'll let you get about 80% as good as DVE on its own (without a SPL meter).

If you want to set the audio channel trims properly, you need a SPL meter +$50

Even then, using DVE to set the picture, will only get you at best about 40% as good as using a colour-meter - which will let you set the colour of grey (giving you a really nice picture), which are readily available second hand for ~$100 (and not that much more new).. and will let you set ALL your TV's / Displays properly (given youve got access to a laptop) - and let you calibrate your laptop screen, and any other computer screens.... then you can on-sell it for abotu the same $..

Cheers,
Bitey


this is fabulously good advise. the ht subforums have a sticky on setting levels with a spl meter. this is the way of doing this. and myself and many many more people have set up their system this way with great results as you'll see in that thread. Its what people have used for years and years. myself certianly since ever been into ht and even with audyssey and all the other auto setup system something that never fails.

I also used thx optimiser
http://www.hometheat...xperts/407cali/
http://www.thx.com/h...izer/index.html
for years for rudimentary picture setup. just the basic elements brightness, contrast and colour I set jsut by eye for naturalness(skin tones). anything further really think you need one of the calibration devices or a professional calibration I think.

#16 alanh

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Posted 19 June 2009 - 09:46 AM

alebonau,
Having read the links above I would much rather use DVE.
The THX disc is based on analog TV settings
Examples where you get mislead
1. PAL countries have never used the lifted black levels. Our analog value for black has been 0 %. In all digital systems the black is 16 steps above 0.
2. If you use the HDMI input there is no need for the hue tests because we have never had a hue control. Testing for PAL phase tests is redundant because HDMI and HD signals have never been PAL coded.
3. The brightness of the large white square may be lower than a small white square. This is because in Plasma screens it is a test of the power supply in the display. So for viewing you would want an average picture level equal to normal program. This is not true of such a large square.


The DVE comes supplied with coloured "glasses". This is to test the Y, Pr, Pb to RGB matrix and the subsequent gain variations between the R G & B channels.

AlanH

#17 DrP

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Posted 19 June 2009 - 10:39 AM

3. The brightness of the large white square may be lower than a small white square. This is because in Plasma screens it is a test of the power supply in the display. So for viewing you would want an average picture level equal to normal program. This is not true of such a large square.

What rubbish. Unless the PSU has a fault showing a 100% white display does not cause any issue with the PSU output.

#18 alanh

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Posted 19 June 2009 - 02:21 PM

DrP,
Both Plasma and CRT displays produce light. The more light produced the greater the current drawn from the power supply. If the power supply regulation is not well regulated than a small are of white draws a much smaller current from the high voltage power supply than for a large area of white. If the display is well designed the variation in brightness will be small, however this is not always the case particularly as the capacitors in the power supply age.

AlanH

#19 DrP

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Posted 19 June 2009 - 02:40 PM

Reeally? Light you say? Never would have guessed. ^_^

Guess what alanh, aged capacitors are faulty capacitors. Grasp that - "Faulty". OK, now go back and re-read my post.

As for regulation, even elcheapo sets have quite reasonable regulation and do not significantly (or for that matter observably) change dot brightness under a 'full white' scenario due to poor power supply design. Some LCD sets deliberately alter the backlight level in response to overall picture conditions but that is by design.

As usual I can back this up with real life data. Can you? Consider calling this a 'hollow' claim as you have in the past (while studiously avoiding providing proof of your own claims no doubt)? Name a selection of 'cheap' PDPs and I'll gather the measurements over the next few days (yes, that's right, I have these sorts of resources at my 'finger tips') specifically to demonstrate how wrong you are.

Edited by DrP, 19 June 2009 - 02:44 PM.


#20 alanh

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Posted 19 June 2009 - 06:45 PM

DrP,
You will note I did not include LCD because the light source is a fluro tube with a diffuser.

Capacitors do not keep their capacity in the presence of heat and time because they dry out. Most display produce enough heat to require an internal fan.

Fault messages will probably not show if the HV drops by 10 % and there is still an image on the screen.

AlanH

#21 DrP

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Posted 19 June 2009 - 06:55 PM

You will note I did not include LCD because the light source is a fluro tube with a diffuser.

Except for the ones that aren't, but hey.... who needs accuracy. ^_^

Capacitors do not keep their capacity in the presence of heat and time because they dry out. Most display produce enough heat to require an internal fan.

Only wet electrolytic caps suffer in the way you suggest. Alternatives have been available for ages. Properly designed (and yes, even the cheapos get it right most of the time) PSUs are built with the variability of electrolytic capacitors taken into consideration. In a correctly working set there is no significant (if any) unintentional change in the brightness.

Fault messages will probably not show if the HV drops by 10 % and there is still an image on the screen.

I have no idea where you got this from, no consumer grade PDP has fault messages advising that voltages are 10% (or worse) out of spec. The first thing a viewer knows when a fault develops is their set has no picture. Are you off in fantasy land again?

Edited by DrP, 19 June 2009 - 06:56 PM.


#22 DrP

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Posted 19 June 2009 - 07:34 PM

Name a selection of 'cheap' PDPs and I'll gather the measurements over the next few days...

I guess the offer has been declined. Best to not respond when one runs the risk of being proven incorrect. :mellow:

#23 MLXXX

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Posted 20 June 2009 - 08:43 AM

3. The brightness of the large white square may be lower than a small white square. This is because in Plasma screens it is a test of the power supply in the display. So for viewing you would want an average picture level equal to normal program. This is not true of such a large square.

I don't want to get drawn into the debate over whether the DVE discs represent good value or are particularly useful.

However it has been mentioned in this HDTVs & HD Capable Displays subforum that the brightness of a plasma screen can be expected to vary depending on how much of the screen is called upon to display white. I can recall Owen referring to this weakness/characteristic on a number of occasions, and he is a plasma aficionado. I have not been able to find a supporting reference on the web this morning, by doing a quick search.

I would note that today's plasma display panels are likely to use techniques to enhance dynamic contrast: dropping the supply voltage overall if the overall scene is dark, or in more advanced arrangements dropping the supply voltage in sectors of the screen. Another technique I have read about is pixel rotation in bright parts of the screen to avoid any particular pixel being pulsed at full intensity for too long and risking temporary or permanent image retention. But I have little personal experience with PDPs.

Edited by MLXXX, 20 June 2009 - 08:45 AM.


#24 Owen

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Posted 25 June 2009 - 12:13 AM

All Plasma panels that I am aware of, including all the high end models, have a negative dynamic contrast characteristic, the greater the average picture level the lower the peak output. The worst case is a full 100% white screen where output is typically half what it is when the display is only asked to deliver a darker scene with only a small amount of bright content.

This G9 Kuro delivers a peak output of 39.5ftl when a small white square (window) is displayed, but drops to only 17.5ftl when a full white screen is displayed.

http://www.ultimatea...tor/index8.html

I donít know why better supply regulation cannot be provided on Plasma panels, but no manufacturer has been able to provide a Plasma with a linear output for input characteristic at any price point, not even close.
CRT displays where prone to similar problems, but only the cheap ones had noticeable issues.

#25 DrP

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Posted 25 June 2009 - 05:15 AM

In every PDP that I've measured so far there hasn't been a significant change in the PSU output voltage, ie regulation appears to be quite good. It may be by some sheer co-incidence that I've managed to only test sets that have a good design.