Do plasma TVs suffer from 30fps double image issues? - Page 2 - AVS Forum
Forum Jump: 
 5Likes
Reply
 
Thread Tools
post #31 of 46 Old 08-15-2014, 12:36 PM
AVS Addicted Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 10,121
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 658 Post(s)
Liked: 623
Quote:
Originally Posted by RyanHomsey View Post
What causes the doubling of images during motion?
Most likely eye movement that isn't tracking the motion perfectly.
Stereodude is offline  
Sponsored Links
Advertisement
 
post #32 of 46 Old 08-15-2014, 01:00 PM
Member
 
hanshotfirst1138's Avatar
 
Join Date: Feb 2011
Posts: 99
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 18
Quote:
Originally Posted by Lara Croft View Post
My problem with the LG-LB6300 right now is that interpolation gives me very bad motionsickness. Btw I have 2 questions below.



1. How come I never seen 30fps double image on my old CRT?

2. Do all modern hdtvs have that 24-30fps double image judder even for normal tv viewing? So far I can see that slight double image on every lcd I tested when I turn off interpolation.







$1,797.99 is alot for a HDTV that can't compete with a $50 CRT.

It's a lot for an HDTV, period. I was interested in plasma, but had major sticker shock when I saw the price.
hanshotfirst1138 is offline  
post #33 of 46 Old 08-15-2014, 01:14 PM
AVS Special Member
 
fierce_gt's Avatar
 
Join Date: Sep 2008
Posts: 4,438
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 812 Post(s)
Liked: 925
Quote:
Originally Posted by jasondjulian View Post
sounds like someone needs to try out a good performing digital projector.. would those display with similar effects as has been mentioned here already? I would think not.
my jvc x35 is far worse with motion than my f8500. although it is also 4x the image size, so it's a lot easier to see.


I think the lesson of this is that it's not the display that you need to fix this, it's the source material, and in a way our eyes.

Displays: Samsung PN64F8500/JVC X35
AVR: Pioneer VSX-1018AH, 5.1 audio
Sources: HTPC(Mediabrowser), PS3, XBOX360, Wii, Sony DVP-CX995V
Control: Harmony One
fierce_gt is offline  
post #34 of 46 Old 08-15-2014, 01:16 PM
AVS Special Member
 
fierce_gt's Avatar
 
Join Date: Sep 2008
Posts: 4,438
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 812 Post(s)
Liked: 925
Quote:
Originally Posted by hanshotfirst1138 View Post
It's a lot for an HDTV, period. I was interested in plasma, but had major sticker shock when I saw the price.
I save money by buying the best, less often.


i'll take spending 3grand on a great tv once every 7-10yrs over spending 800 on a display I immediately want to upgrade

Displays: Samsung PN64F8500/JVC X35
AVR: Pioneer VSX-1018AH, 5.1 audio
Sources: HTPC(Mediabrowser), PS3, XBOX360, Wii, Sony DVP-CX995V
Control: Harmony One

Last edited by fierce_gt; 08-18-2014 at 11:50 AM.
fierce_gt is offline  
post #35 of 46 Old 08-15-2014, 02:41 PM
Senior Member
 
Josh128's Avatar
 
Join Date: Nov 2013
Posts: 402
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 192 Post(s)
Liked: 70
Quote:
Originally Posted by RyanHomsey View Post
What causes the doubling of images during motion?

Are you saying we are collectively imagining it or something else is the cause?
Its just the way our eyes and brain perceive 30hz animation / movement. Ive found the illusion to be much more pronounced with brighter, more colorful content. Darker scenes appear much smoother to my eyes at the same 30hz.

Last edited by Josh128; 08-15-2014 at 03:07 PM.
Josh128 is online now  
post #36 of 46 Old 08-15-2014, 09:28 PM
ADU
AVS Special Member
 
ADU's Avatar
 
Join Date: Apr 2003
Posts: 6,461
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 121 Post(s)
Liked: 173
Quote:
Originally Posted by Josh128 View Post
Its just the way our eyes and brain perceive 30hz animation / movement.
What he said.^

I'm surprised some of the film buffs here aren't familiar with this phenomena because it occurs in movie theaters as well, where the projected frame/flicker rate is normally 48fps (twice the 24fps rate of film). Or at least it did when film was still in use. I think the first time I became acutely aware of it was during some of the space scenes in Star Wars. When the starfields moved across the screen, all the stars magically transformed into binary systems.

The double images occur because your eye smoothly tracks the movement of the object across the screen. Since each frame is displayed twice though, the 2nd image of the object appears in a slightly different place on your retina than the first, even though they're both physically at the same spot on the screen. The faster the object is moving, the bigger the distance between the two images of the moving object.

The effect only occurs though in display systems which refresh/flicker at double the rate of the recorded images, like a motion picture projector, or a 60Hz CRT or plasma display. Since LCD/LEDs don't normally flicker, you get "smearing" on them instead, for much the same reason. The 96Hz Cinema Smooth option on Samsung plasma displays will more closely approximate that smeared LCD look by displaying each frame 4x, if that's what you prefer. But it only works with 24Hz inputs.

ADU

Last edited by ADU; 08-16-2014 at 12:04 AM.
ADU is offline  
post #37 of 46 Old 08-15-2014, 10:40 PM
Senior Member
 
ChadThunder's Avatar
 
Join Date: Aug 2013
Posts: 310
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 49 Post(s)
Liked: 52
Yes plasmas especially suffer from double images but you will probably only see it when tracking bright objects in fast motion as some people have noticed, if you keep your gaze fixed on one location of the screen you won't see much of that affect

It's not just plasmas, all sub-field driven displays have quirky motion artifacts when the framerate falls out of sync with the refresh rate, you might experience judder or colors breaking up like an oil painting or something else. The easiest way to explain subfield driving is maybe to say that bright objects are drawn "more times" than darker objects and if an object changes it's color or intensity even slightly it will appear at a different time in the next frame

RyanHomsey and orion2001 like this.
ChadThunder is offline  
post #38 of 46 Old 08-15-2014, 11:18 PM
ADU
AVS Special Member
 
ADU's Avatar
 
Join Date: Apr 2003
Posts: 6,461
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 121 Post(s)
Liked: 173
Quote:
Originally Posted by RyanHomsey View Post
IMO, albeit less accurate, the smearing/blurring inherent in LCD based panels seems less distracting.
See my comment above re Cinema Smooth.

Quote:
Originally Posted by RyanHomsey View Post
My TV upgrade path has been Sony XBR970 34" CRT --- > LG LD520 42" CCFL LCD --- > Samsung 60" F5350 Plasma. When I purchased the LG LCD in 2010 I literally bought/returned 3 different LED/CCFL LCD panels and eventually just gave up when I realized I wasn't going to get the same performance as my CRT. I dont see the double on my CRT (still running strong in the kids bedroom) but it is much smaller than the 60" plasma, which is probably the cause of that.
The double images won't be as obvious on an interlaced CRT like the XBR970... unless you feed it 30fps content at 480p, and switch the TV to Progressive mode, if your model allows that.

I don't recommend using 480p/Progressive mode though, because the phosphor lag is less noticeable on Sony CRTs in the interlaced display modes.

ADU
ADU is offline  
post #39 of 46 Old 08-16-2014, 05:13 AM
Senior Member
 
RyanHomsey's Avatar
 
Join Date: Oct 2006
Posts: 331
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 111 Post(s)
Liked: 39
Quote:
Originally Posted by ChadThunder View Post
Yes plasmas especially suffer from double images but you will probably only see it when tracking bright objects in fast motion as some people have noticed, if you keep your gaze fixed on one location of the screen you won't see much of that affect

It's not just plasmas, all sub-field driven displays have quirky motion artifacts when the framerate falls out of sync with the refresh rate, you might experience judder or colors breaking up like an oil painting or something else. The easiest way to explain subfield driving is maybe to say that bright objects are drawn "more times" than darker objects and if an object changes it's color or intensity even slightly it will appear at a different time in the next frame

Makes sense. Thanks for the explanation.

The idea that it's simply inherent in the source frame rate doesn't add up, as I regularly go to the local big screen cinema and have never noticed such issues.
RyanHomsey is offline  
post #40 of 46 Old 08-16-2014, 07:40 AM
Senior Member
 
Josh128's Avatar
 
Join Date: Nov 2013
Posts: 402
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 192 Post(s)
Liked: 70
Quote:
Originally Posted by ChadThunder View Post
Yes plasmas especially suffer from double images but you will probably only see it when tracking bright objects in fast motion as some people have noticed, if you keep your gaze fixed on one location of the screen you won't see much of that affect

It's not just plasmas, all sub-field driven displays have quirky motion artifacts when the framerate falls out of sync with the refresh rate, you might experience judder or colors breaking up like an oil painting or something else. The easiest way to explain subfield driving is maybe to say that bright objects are drawn "more times" than darker objects and if an object changes it's color or intensity even slightly it will appear at a different time in the next frame

I have to disagree that particular illusion is caused by plasma subfield drive as it is just as pronounced on CRT,which doesnt have anything remotely close to subfield drive. Ive seen this effect DECADES before I owned my first plasma display. Starting with the Playstation/ N64 generation, 30 fps polygon graphics became the norm, as the processors were simply not fast enough to redraw scenes at 60 fps for most games. I started noticing this "30fps" illusion back in 1996 when I purchased an N64 as a kid and played Super Mario 64.

Game content / output is much purer and harsher than film content and in many ways, much less dynamic (you dont see unchanging, side scrolling objects in movies very often, but you do in games) and this is a big factor.

That said, I do think your subfield drive explanation can contribute to some dark image "ghosting" or "trailing" on some content-- as I have experienced that on my plasma (almost exclusively in 480i mode in dark scenes, game and video content both), but it happens both with 60fps content and 30fps content and is not specifically related to 30fps as the effect we are discussing here.

The big difference, and proof of this, is that you can capture the subfield "ghosting / trailing" effect in a photo of the screen because its actually happening, while the simple 30fps double image illusion that we are discussing here can NOT be captured in a photo because its just an optical illusion.
Josh128 is online now  
post #41 of 46 Old 08-16-2014, 10:18 AM - Thread Starter
Member
 
Lara Croft's Avatar
 
Join Date: Aug 2014
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 0
Keep in mind I'm using an IPS panel as well if that means anything.
Lara Croft is offline  
post #42 of 46 Old 08-16-2014, 09:21 PM
AVS Addicted Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 10,121
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 658 Post(s)
Liked: 623
Quote:
Originally Posted by ADU View Post
What he said.^

I'm surprised some of the film buffs here aren't familiar with this phenomena because it occurs in movie theaters as well, where the projected frame/flicker rate is normally 48fps (twice the 24fps rate of film). Or at least it did when film was still in use. I think the first time I became acutely aware of it was during some of the space scenes in Star Wars. When the starfields moved across the screen, all the stars magically transformed into binary systems.
Most premium projectors were 72Hz. They strobed the lamp (with a shutter) 3 times per film frame.
Stereodude is offline  
post #43 of 46 Old 08-17-2014, 09:48 AM - Thread Starter
Member
 
Lara Croft's Avatar
 
Join Date: Aug 2014
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Liked: 0
That this little info was interesting that I found on another site.

With my usual tests based on PixPerAn, I was able to detect the usual overdrive errors (negligible halos that compass moving objects) and a certain degree of pixel lag, which are still common to LCD displays of late. Low-tone Smearing was present but did not cause any major issues with real-world contents.

ghosting caused by pulsing backlight. During the extended test period, I was able to detect highly visible doubling effect (original image accompanied by a ghost image) during fast motion
Attached Thumbnails
Click image for larger version

Name:	blur-1.jpg
Views:	32
Size:	31.8 KB
ID:	215969   Click image for larger version

Name:	blur-2.jpg
Views:	28
Size:	30.7 KB
ID:	215977  
Lara Croft is offline  
post #44 of 46 Old 08-17-2014, 07:36 PM
Member
 
jasondjulian's Avatar
 
Join Date: Dec 2013
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Liked: 73
OK, so we've firmly established that for moving images, LCDs suck. Got it.
mailiang likes this.

Panasonic TC-P55S60
Sony S5100 BD-Player
RCA 5 disc DVD HTIB for 5.1 Surround
jasondjulian is offline  
post #45 of 46 Old 11-08-2014, 04:29 PM
Member
 
hanshotfirst1138's Avatar
 
Join Date: Feb 2011
Posts: 99
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 24 Post(s)
Liked: 18
Quote:
Originally Posted by jasondjulian View Post
OK, so we've firmly established that for moving images, LCDs suck. Got it.

Yes, well, it was all I could afford .
hanshotfirst1138 is offline  
post #46 of 46 Old 11-08-2014, 05:09 PM
Senior Member
 
Josh128's Avatar
 
Join Date: Nov 2013
Posts: 402
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 192 Post(s)
Liked: 70
Just a quick update regarding the dark image "ghosting/trailing" I mentioned earlier-- I managed to eliminate it completely by turning the "Digital Clean View" option to OFF. I mentioned this in the F4500 thread a couple months ago, but its worth mentioning here because if you have it enabled, the F4500 will indeed sometimes show trailing /doubled images, usually only in darker scenes/content.

Displays: Samsung PN51F5300BFXA, PN51F4500AFXA, PN51F4500BFXA

Josh128 is online now  
Reply Plasma Flat Panel Displays



Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off