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Common Plasma Terms and Acronyms

41K views 38 replies 29 participants last post by  John Hooper 
#1 ·
New to the Plasma forum and wondering what all the 'lingo' is that everyone keeps referring to? This may help ...

Common Plasma Glossary of Terms

break-in / break in period / panel Aging

Common convention is that after ~100 to 200 hours of displaying alternating full white to full dark the plasma discharges have become 'stable' and the plasma can have "final" display settings calibrated. Tweaking the display settings before this time will result in (potential) settings that will need to be re-adjusted to get the best picture quality. Break-in will help with image rentention.

(Thanks Pioneer http://www.avical.com/articles/avica...in-report.html )
Quote:
There is no question that these displays need breaking-in. Out of the box, the default settings rendered a grayscale that was too warm as well as green. During the 213-hour break-in process, the display became warmer and more green - not dramatically so, but enough to warrant putting in some hours before making an appointment for calibration. Plus, it's never a bad idea to wait a few weeks to ensure that you don't have a lemon anyway.
Discussion:

* http://www.avsforum.com/avs-vb/showthread.php?t=949107 Master Burn-In/IR/Break In Thread Part II: All Posts Here Only

See also: IR, MLL, PQ

burn in

Long term image rentention, even after the plasma has been turned off, cooled, and turned back on. Do. Not. Want.

Early plasmas in the 2000's suffered from this. It is mostly a non-issue now a days but it doesn't hurt to be cautious.

See also: IR

buzzing - (Thanks Panasonic) http://www.highdefforum.com/134709-post4.html
Quote:
"The picture scanning drive circuits operate at high frequencies and powers.

It is these circuits that cause the buzzing sound. The circuits are used to

create both the picture and reuse energy to keep the unit efficiency high

and panel heat emission low. This over-heating control is very important on

the panels that do not use fans i.e 37” and 42” The resulting loss of fans

makes for a quieter panel operation."

(Thanks greenland) http://www.avsforum.com/avs-vb/showt...8#post18335568 The Official LG xxPK550 Owner's Discussion Thread (no price talk)
Quote:
"According to some people with expertise on the subject, including D-Nice, the move by Plasma makers to go to the bonded single sheet of glass design, is causing the normal buzz from plasma panels to be heard more. Apparently, the older design, with an additional sheet of glass in front, helped to contain some of the buzzing sound."
Calibration

Tweaking the input color channels to give a "better image." The final results are limited to the quality of the meter, optional software such as CalMAN or ControlCAL, and the skill/experience of the calibrator.
Examples: (i.e. Descriptions of calibration)

* Chad B - LG 50PK550 plasma http://www.avsforum.com/avs-vb/showt...8#post18358288 )

* Cleveland Plasma - Panasonic 50G25 calibration report https://clevelandplasma.com/store/20...g20__tc_pxxg25

Dithering

A processing effect where colors are inter-mixed to simulate a wider gamut then the device is physically able to generate natively.

Panasonic plasmas owners may be interested in (Thanks redwolf4k) http://www.avsforum.com/avs-vb/showt...6#post19127876 tc-p50s2 crappy picture...
Quote:
If you do not like cinema as mentioned in the original post, your probably going to want to use Custom over Standard mode, as standard mode uses heavy dithering, which will give a very grainy look. Custom mode however, has little to no visible dithering, like cinema mode, but is not soft like cinema mode.
Discussion:

* no specific thread unfortunately -- search for your specific model you are interested in

Reference:

* http://en.wikipedia.org/wiki/Dithering#Examples Examples of color dithering

DSE - Dirty Screen Effect

Lighter and darker streaks on the panel. Most visible when the camera pans vertically over a solid color background. If after using a microfiber cloth and distilled water to clean the outside of your plasma the streaks don't go away then you have DSE.

(Thanks mittene) http://www.avsforum.com/avs-vb/showt...3#post15940293 How common is "dirty screen effect" for current Pioneer 9G Owners?
Quote:
I think it would be helpful to distinguish what "dirty screen effect" is. I've always thought that it referred to the faint grayish vertical streaks that can be seen when there's a panning shot across a relatively lighter-colored background (if the background is a solid color or at least almost uniform in color). The vertical streaks that appear are fairly uniform in width, and look fairly uniformly spaced from each other. And as I understand it, it has nothing to do with any other kind of screen uneveness, residue on the screen, or the purple blobs that some people can see on their screen when the TV is turned off or on and showing a black/blank screen while light hits it in a certain way.

Example:
http://www.avforums.com/forums/attac...ap-picture.jpg exaggerated "artist's rendition" of DSE
Discussion:

* http://www.avsforum.com/avs-vb/showthread.php?t=1113122 How common is "dirty screen effect" for current Pioneer 9G Owners?

FI - Frame Interpolation

See: Soap Opera Effect

floating blacks

While watching a movie the processing algorithm in the plasma will dynamically adjust the darkest levels making them lighter or darker resulting in flickering "grays." One solution is to adjust the brightness lower, or buy a professional model (Panasonic), or (worse cast) from a different manufacturer (Pioneer).
Discussion:

* http://www.avsforum.com/avs-vb/showt...6#post18361266 hydrogin explaining levels 0-255

* http://www.avsforum.com/avs-vb/showt...6#post18361266 hydrogin's technical explanation.

Holy Grail

The mythical über plasma that does everything perfect. Some bibles describe the Pioneer Kuro as being God's chosen. Some heretics would argue that the professional Panasonic bible should be used instead. You decide which religion is "right" ...

* http://www.avsforum.com/avs-vb/showthread.php?t=920011 Official Pioneer Kuro Pictures Thread.......

* http://www.avsforum.com/avs-vb/showthread.php?t=733641 TH50PHD7UY and TH50PH9UK - IamAnoobieCheez beautiful pics

* http://archive2.avsforum.com/avs-vb/...d.php?t=261309 The _classic_ "Steaming Rat"

input lag - The delay from when an input (video) signal is detected to when it has been decoded, processed, and displayed.
Discussion:

* http://www.avsforum.com/avs-vb/showthread.php?t=1166196 The Official Plasma Input Lag Thread.

IR - Image Retention

The short term effect where "static" images displayed for long times tend to have a "ghost effect". Game Menus, HUDs, and Cable TV LOGOs tend to be the worst.
Discussion:

* Thanks borcth! http://www.avsforum.com/avs-vb/showt...1#post18378421 The Official LG xxPK550 Owner's Discussion Thread [no price talk]

See also: burn in

ISF - Imaging Science Foundation

A type of display mode that has certain requirements for image quality. Compare and Contrast to THX mode.

Judder

(Thanks Nektarios) http://www.avsforum.com/avs-vb/showt...8#post19389998 why don't plasmas have a higher refresh rate?
Quote:
> In plasma 25/30fps material just seems jerky/sudden and creates more "double vision" by showing same frame 2 times a row without any buildin blurring

This "double vision" you are talking about, is called Judder and is what I am talking about. On 60fps (or the same fps as your refresh rate is set to) you should not see any blurring/judder on a CRT and plasma (most plasmas leave phosphor trails though).
line bleed (Thanks Dayton!)

When a horizontal or vertical image results in ghosted line extending to a neighboring image due to power not being evenly distributed along the row or column. This is common when a scene consists of a lot of lines for example one containing window blinds, stairs, or the like.

Masking

Rich Harkness' ingenious method of adding black masking tape all around the plasma in order to bring out the color saturation of the plasma.

MCFI Motion Compensated Frame Interpolation

It is not needed on plasmas.
Discussion:

* http://www.avsforum.com/avs-vb/showt...6#post19389986 why don't plasmas have a higher refresh rate?

MLL - Minimum Luminance Level
Also known as: black level, background luminance, idle luminance, pre-discharge

The lower the number, the darker the image can be. As plasmas age, they require more voltage which drives up the MLL. Luminance can be measured in either the footlambert (fL) for Imperial units , or in candela (cd/mq) for SI units. (Note: 1 fL = 3.426 cd/m^2)
Discussion:

* http://www.avsforum.com/avs-vb/showthread.php?t=1167339 Panasonic ~ 0.008fL to ~ 0.023fL

See also:

* http://finiteblack.blogspot.com/ Taking pictures of your MLL.

References:

* http://www.crompton.com/wa3dsp/light/lumin.html - Brightness, Luminance, and Confusion

* http://en.wikipedia.org/wiki/Foot-lambert

Moving Picture Resolution

The cheaper plasma's do NOT have a native resolution of 1080, thus the scaler has to "fake" it when given a 1080 source by taking advantage of limitations of human perception to "effectively" display a higher resolution. The "tricks" to fake it are different when the image is static or dynamic, and thus the standards to measure what is the "perceived resolution" needs to be modified.
Discussion:

* http://www.avsforum.com/avs-vb/showt...1#post14659401 Moving Picture Resolution ?

panny - Panasonic

What Panasonic plasma owners/fans affectionately call the Panasonic plasma models.

Phosphor Trailing

The "ghost" effect of a moving image.

pio - Pioneer

What Pioneer plasma owners/fans affectionately call the Pioneer plasma models.

PQ - Picture Quality

Overall quality of the image. Encompasses:

- colors (purity, saturated, muted, washed out, tinted, gamut)

- edges (sharp, crisp, fuzzy, graininess)

- black levels ("true black", grey, gamma)

- motion compensation (motion blur)

refresh rate

How many times the plasma can update/refresh the display. The most common setting is 600 Hz which is 10 subfields each refreshing at 60 Hz.

Notes:

* This is not to be confused with the movie playback of 24p as that is frame rate of the source input material where as refresh rate is the frame rate of the output display. The frame rate and refresh rate are uncoupled / independent of each other. e.g. 24p @ 48 Hz (may have flicker), 24p @ 60 Hz (default), 24p @ 72 Hz (new emerging standad), etc. Generally a higher refresh rate results in a more "stable" image.

* Also note that refresh rate is independent of input lag.

See also: input lag
Discussion:

* http://www.avsforum.com/avs-vb/showthread.php?t=1285072 why don't plasmas have a higher refresh rate?

rising blacks - Forthcoming...

sammy - Samsung

What Samsung plasma owners/fans affectionately call the Samsung plasma models.

Service Menu

The (advanced) calibration options tucked away in the firmware. Requires a secret remote code to activate / enter.

Soap Opera Effect (Thanks Greg Black!)
Discussion:

* http://www.avsforum.com/avs-vb/showt...1#post18414721
Quote:
The "soap opera effect" is a phrase used to describe the effects of frame interpolation -- basically, it's an algorithm that averages the difference between the pixels of the current frame and the next frame of video or film-based content, then inserts newly created frame(s) in between. It essentially removes the "look" of 24 frames-per-second film and smooths it out to look like something shot on video tape (30 fps), such as the typical soap opera would be -- although it actually looks more extreme than that, IMO. Some plasmas do have this, erm, "feature", but it seems much more prevalent on LCD sets.
Videophile

The geek who takes PQ way too serious compared to your average Joe. Everyone has a hobby -- we just happen to like tweaking our displays to get the best picture possible. We're not obessive, just passionate (well most of us!) Just keep the "flaming" friendly between Plasma, LCD, LED, DLP, and Projectors. ;-)
 
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#2 ·
Feel free to post suggestions / corrections, and I'll edit the top post.


Cheers
 
#3 ·
Might call it "glossary of terms" vs. acronyms.


Some other thoughts/suggestions:


IR - should be distinguished from "burn-in", i.e. IR is temporary?

PQ - does this also include motion (lack of motion-blur)?


Should this include:

- Burn-in

- Refresh rate (and how this does not directly influence input lag)
 
#4 ·
"MLL - Minimum Luminance Level

The lower the number, the darker the image can be. As plasmas age, they require more voltage which drives up the MLL."


You might want to fix this.
 
#5 ·
I'm surprised this hasn't been created before this.. questions like "What does MLL mean" come up all the time...


You may want to:


break in / Panel Aging


Here's a link to data supporting this (data from a Pioneer): http://www.avical.com/articles/avica...in-report.html

Quote:
There is no question that these displays need breaking-in. Out of the box, the default settings rendered a grayscale that was too warm as well as green. During the 213-hour break-in process, the display became warmer and more green - not dramatically so, but enough to warrant putting in some hours before making an appointment for calibration. Plus, it's never a bad idea to wait a few weeks to ensure that you don't have a lemon anyway.
 
#7 ·
Although a great idea I do see one very small issue with it. You may need to be more descriptive with regards to synonyms of some terms.


For instance it would clear a lot of confusion to explain that MLL has the following synonyms

MLL = Minimum Luminance Level which is synonymous with:


(black level)

(background luminance)

(idle luminance)

(pre-discharge)


Anyway, just a suggestion.


Cheers
 
#9 ·
@Calvin,

You have a description or link handy so I can make sure I'm understanding MLL correctly please?


@Dayton

You have a description or link handy so I can make sure I'm understanding line bleed correctly please?


@jader201

Great catch -- PQ should include motion compensation. Updated.

Updated IR, refresh rate, burn-in.


@Spleen

Agreed that Glossary is more accurate. Done.

Enjoy the Holy Grail entry :)


@turbe

Thanks for panel aging! Added.


@xrox

Great idea! Added "Also known as: ..."

Everyone -- still looking for a good description of

- rising blacks

- 600 Hz sub field

- x:x & 3:2 pulldown


Thanks!
 
#11 ·
your refresh rate line is screwed up. hz != fps


24 and 48 fps are frame-counts, not hz. 600 hz is 10 subfields each refreshing at 60hz so the actual refresh is 60hz for the total panel, not 600. I'm not sure on the mechanics of displaying 72fps, but I know that you need to correct that.
 
#12 ·
line bleed - when a horizontal or vertical image results in ghosted line extending to a neighboring image, due to power not being evenly distributed along the row or column. This is common when a scene consists of a lot of lines for example one containing window blinds, stairs, or the like.
 
#13 ·

Quote:
Originally Posted by dlplover /forum/post/19432129


your refresh rate line is screwed up. hz != fps


24 and 48 fps are frame-counts, not hz. 600 hz is 10 subfields each refreshing at 60hz so the actual refresh is 60hz for the total panel, not 600. I'm not sure on the mechanics of displaying 72fps, but I know that you need to correct that.

Technically 24p IS a frame rate, but you are right, that is independent of refresh rate. Does it read better now?
 
#15 ·
@Dayton - Thanks for the line bleed info !


@dlplover - Thanks for the sub-field info and refresh rate corrections.


@Speck - Thanks for the soap opera catch, and the link for refresh.


@Vlad - Thanks for dithering and DSE. Which manufacturers / models does dithering seem to effect the most? Are you happy with the flicker / judder description please?
 
#16 ·
Quote:
Originally Posted by turbe
I'm surprised this hasn't been created before this.. questions like "What does MLL mean" come up all the time...
Yeah I was rather surprised about that too. Instead of just bitching about it,I decided to do something about it.



Plus I get to learn some cool tech talk while I research the next plasma I want.
 
#19 ·
Wow as soon as this thread got stickied it came to a grinding halt



Here are some more terms from xrox as posted in This Thread :


1 - Phosphorescence - there is a long afterglow component of phosphors that can be seen even when the display is off. It is very very faint however and eventually dissipates.


2 - Residual charge - Plasma displays use dielectric charges to control the on or off states of the pixel. If there is a slight residual charge left when the pixel is turned off the next time it turns on the pixel will be slightly brighter than normal. This will show up as a ghost image on a dark screen. You can tell it is residual charge because the ghost image is slightly brighter than the dark background. This ghost image is transient and easily removed by either a full white screen or watching full screen material for a few hours.


3 - MgO Sputtering - High energy discharge in Plasma displays causes Magnesium Oxide to sputter and deposit onto the phosphor and adjacent pixels. The result is a long lasting ghost image that can take many days to remove. It can be seen as a slightly darker image on a full white screen. Ironically, a full white screen for many hours is the best course of action to resolve this issue as it normalizes the deposition of MgO to all pixels (evens it out)


4 - Phosphor aging - Permanent aging of the phosphor material that causes a slightly darker ghost image that is irreversible.
 
#21 ·

Quote:
Originally Posted by RobbyTV /forum/post/19743061


not much info on this?

The literature that I've read commonly states that the two mechanisms in PDP that age the phosphors are:
  • Solarization - High energy UV photons (light) damage the phosphor
  • Ion and electron impact - Charged particles impacting and damaging the phosphor


Modern Plasma displays have higher Xenon content which emits lower energy UV photons and thus less phosphor damage and longer life. Also, newer phosphors can be inherently more resistant to the above mechanisms.
 
#23 ·

Quote:
Originally Posted by _Michaelangelo_ /forum/post/19431925

Everyone -- still looking for a good description of

- x:x & 3:2 pulldown

3:2 (or 2:3) pulldown is a standard method of displaying 24 fps movies on 60 Hz (usually 30 fps interlaced) displays.


All movies are shot at 24 fps. Movie theatres display the movies at 48 Hz, showing each frame twice.


Here is a timeline comparing different display techniques:

Code:
Code:
Time in 1/48th sec steps | 0----1----2----3----4----5----6----7----8--->
24 fps film stock        | A.........B.........C.........D.........E...
48 Hz film projector     | A....A....B....B....C....C....D....D....E...
60 Hz TV w/ 2:3 pulldown | A...a...B...b...B...c...C...d...D...d...E...
48 Hz "cinema mode"      | A....A....B....B....C....C....D....D....E...
Notes:

- The original film consisted of the frames ABCDE...

- For the TV signal, I have used upper and lower case to denote the upper and lower fields of the interlaced display. If the display is progressive, then simply ignore the case.

- So basically 3:2 pulldown is a compromise. We show frame A for 2 fields, then show frame B for 3 fields, then C for 2 fields, then D for 3 fields, etc. This produces a noticeable "judder" effect whenever there is motion on the screen, since your brain can notice that the movement is not smooth.

- Note that "cinema mode" is pretty much exactly what you would get in a movie theatre with a standard film projector. There will still be a noticeable flicker and jerky motion, because your brain can still notice that each frame is being displayed twice, but it's just not as jerky as 3:2 pulldown is.
 
#24 ·
can any body here or post a link to explain to me what pull down means

i allways see 2.2 and 3.2 pull down listed does it have something to do with

framrates in moives?? like i said iam just geting back in to tv tech and it seems

that this pull down talk is really imporant
 
#25 ·
Could some explain the various “picture modes” that most TV’s have, such as Vivid, Custom, THX, etc., and explain why different modes are even necessary? For example, if you adjust settings to be equal in two different modes do you get the same picture quality, and if not then why not.
 
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