Motion Judder

snadge

Active Member
Ive recently purchased a LG5700 32" 1080p TV

its great quality but on large fast moving objects or panning scenes it seems to judder and sometimes flicker (if the object is bright white and big)....

my last TV seem to just blur it (slow response time maybe?) but this one judders - i think I may have preferred it blurred - judder/flicker looks horrible

i understand most LCD TV's get this... and its due to interlacing/de-interlacing

ive also noticed some banding albeit a little bit but is noticeable sometimes - im just wondering if i should take it back - but then again, i may end up with a worse set...

is judder normal?
 

Shompola

Active Member
Yes it is common. One of the selling points of the sets with so called 100Hz refresh rate is that they will reduce judder and blur.
 

snadge

Active Member
thanks then i know i havent been ripped off with a crap TV hehe
 

snadge

Active Member
its a LG 5700 32", using a SKY+HD via HDMI on 1080i and TV on JUST-SCAN for 1:1 Pixel Mapping but also does it on 16:9 (with 5% overscan)

its on all programs be it movie channels or other channels
 

Nielo TM

Distinguished Member
that shouldn't be happening

Just to clarify, what do mean by judder and sometimes flicker?

In my book, judder refers to uneven motion where one frame is displayed longer than the other.
 

snadge

Active Member
on some scenes when camera pans around left/right (medium speed) it judders - after some checking online it seems to be related to interlacing/de-interlacing - it similar to 3:2 pulldown judder

when paused you can see two frames mixed together

as far as i know this is normal for lcd tv's

the model has just become obsolete to newer versions and LG have removed all older tv's - no 100hz
 

Nielo TM

Distinguished Member
it's not normal for LCDs, but the LG you have may contain a poor de-interlacer.

Have you tried switching to 720p? If the problem is truly caused by de-interlacing, you shouldn't have any problem with 720p
 

snadge

Active Member
happens on both 720p or 1080i...

all SKY channels are broadcast interlaced - 576i or 1080i so even if i set the SKY+HD BOX to 720p its still got to de-interlace 1080i to 1080p then downscale it to 720p - so artifacts still get through... however it doesn't look any better - exactly same - i have some recorded programs and they get same judder on 1080i or 720p

however my TV is a 1080x1920 TV so its best on 1080i
 

Nielo TM

Distinguished Member
De-interlacing doesn't produce motion artifacts if done correctly. The de-interlacers embedded in SkyHD STBs vary in quality but they do the job just fine.

The fact of the matter is, you shouldn't be seeing motion judder with Sky HD as it's broadcasted in 1080i50.

Have you tried any other source by any chance?
 

snadge

Active Member
judder and blur is normal on lcd's hence the need for 100hz/200hz etc

i think im probably being fussy but i didnt notice it much on my old cheapy bush lcd 32" that seemed to blur it but this LG has les blur but makes judder more noticeable....

it has freeview built in and i have a HDMI 1080p upscaling dvd player
i will try em out but and see if i notice any judder on those

like i say i think im just being fussy, when it happens and i pause it you see 2 frames mixed together

looks summit like this:- (could be slow de-interlacing)
motion_bench_05_PDP.jpg
 

Nielo TM

Distinguished Member
judder is not normal for LCDs, but blur is (due to the driving mechanism and high pixel transition times)

The image you've posted is showing A and B frames (odd and even), which is normal when pausing interlaced video in field mode.



PS: You could be confusing judder with the effects of low-motion content.
 
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snadge

Active Member
wots that? (low motion content)

its like when the camera pans around left or right it judders , slowly and it doesnt - fast and obviously you cant notice it cos its too fast but medium speed pans and the objects in the video judder and when paused you see mixed frames...

is this a problem or am i being fussy?

my last LCD was a cheapo bush with summit like 12ms or 24ms - cant remember but i never noticed it on that , it used to blur on pans... this LG is clearer but you can see judder... its like its lagging behind or summit

you dont see it all the time just on some occasions....

it also seems to flicker when it pans in any direction when theres lots of bright white on the screen

thanks for your help by the way - just weve had this tv almost 4 weeks and i need to decide whether or not i should take it back before 30 day rule is out...

it has a few problems which i can live with - even slight banding/clouding/light dispersal issues which is annoying sometimes....

1. buzzing from screen (invertors) when fresh contrast is on / backlight dims
- fixed by disabling fresh contrast / backlight on 100%
2. Housing vibrates off sound bass
- fixed by tuning down bass
3. Some banding/clouding issues
- very acute but sometimes annoying as its new set and last TV got banding that worsened after warranty was up
4. Judder on panning shots

..so as u can see im getting annoyed... but problem is they dont have ay other 1080p TV's for same price so if i got a swap it would probs have to be a 768p set as theyre same price (£350)
 

snadge

Active Member
will enabling FILM MODE make any difference?

also , it has CINEMA , SPORTS , GAME modes but i have it on OFF...

ive read somewhere that SPORTS and GAME modes reduce motion blur/judder...

perhaps I should try one of those with FILM MODE enabled
 

Nielo TM

Distinguished Member
wots that? (low motion content)

The term Low-motion is referred to 24, 25 and 30p contents, because they don't have sufficient information between the frames to produce smooth-continuous motion. In other words, along with motion, you'll also perceive individual frames.

PS: For 1080p models, I think LG used Sharp's ASV panel. Is it possible to take a photograph of the pixels?
 

snadge

Active Member
The term Low-motion is referred to 24, 25 and 30p contents, because they don't have sufficient information between the frames to produce smooth-continuous motion. In other words, along with motion, you'll also perceive individual frames.

PS: For 1080p models, I think LG used Sharp's ASV panel. Is it possible to take a photograph of the pixels?

thanks for your help i appreciate it...

I only have a 2megapixel camera phone... and these scenes happen far and few between - i will have to find some on my recordings on SKY+HD

its not like Blu-Ray judder (Frame Dropping which causes a stutter once or twice a second) this is like constant stutter/flicker 5-10 times a second when camera pans around at certain speeds the objects in screen appear to flicker/stutter several times - when paused you see mixed frames

what is it you want me to take picture of? one of these scenes PAUSED?
 

Nielo TM

Distinguished Member
Is it possible for you to return the set? Because there may be a fault with the set from what you've described.
 

snadge

Active Member
ive had the set almost 30 days - it has 5 years warranty but after 30 days you cant return for refund or exchange....

and they (richer sounds) dont have any more 1080p sets for same price so i would have to downgrade...

also,
it has other issues...
buzzing from invertors in dark scenes
some banding/clouding/light issues - (looks like thumb print on screen and some dark patches - again only noticeable on certain colours and panning shots)
Vibrating case off bassy sounds

...and now this flicker is annoying
 

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