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Possible Local Dimming problem Samsung QE55Q70R?

bluin

Member
I've had the Samsung QE55Q70R for a few days and on the whole I've been very impressed but noticed that end credits on films and when the screen is black apart from some white text in the middle that the text seemed very dark (problem disappears when bringing up the menu - text/credits appear bright and normal). *I should add subtitles are not a problem.

So i ran the following local dimming test which uses the white square and circle moving around a black screen and was surprised to see that the smaller the little white square/circle became the darker it appeared - the smallest becoming almost grey in colour (square shape affected the most).

Link to the local dimming test i used - would be interested in other Q70R results - especially the Samsung QE55Q70R .


I also noticed that the direction the leading edge of the shape moved in, it would become darker than the rest of shape as it moved around the screen - and as the shape became smaller it looked as though is was moving in and out of shadow.

And lastly as the image begins to speed up the image becomes blurry (expected) but seems excessive with the above issues added to the equation.

Question is - is this norma? As I've been reading a lot today about FALD and black crushing - and now i'm confused as to what i'm supposed to expect. But no mention of this issue - that i've come across yet...

*The TV is calibrated via a combination of main pro review recommended settings and personal preference - but having little affect regarding this issue. And all other colour calibration tests seem normal, great even - to my eyes.
 
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bluin

Member
Update - things I've tried to resolve issue but with no success:
  • Software update to latest version
  • Factory Reset
  • Unplugging all external devices
  • Called Samsung - but crib sheet responses - and telling me to return TV (Probably will - but they couldn't give an answer as to whether this was a known issue. Plus, now out of stock.)
  • Different calibration settings
  • Banging head rhythmically against table
 

bluin

Member
So - you mean the white text/image dims the longer it stays on screen?
Thanks for reply.

No, the smaller the shape gets the darker it becomes (but retains same level of darkness) - to the point that it's almost grey when it's the smallest square rather than bright white (but stays same consistent blotchy colour of grey).

*Although it does shadow as it moves between local light sources (local dimming spots i guess) - but this isn't as much as a concern as the radically different lack of light between large and small images on a black background.

As mentioned - first noticed it when film credits rolled and then really noticed it when watched a 4k firework demo - really muted colours and very sporadic. I may try and film it - but is pretty much as described.

TL;DR

Basically - small bright images on a predominantly black background are very dull/muted (not the brightness/intensity they should be - nowhere near).
 
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cuke2u

Well-known Member
I've had the Samsung QE55Q70R for a few days and on the whole I've been very impressed but noticed that end credits on films and when the screen is black apart from some white text in the middle that the text seemed very dark (problem disappears when bringing up the menu - text/credits appear bright and normal). *I should add subtitles are not a problem.

So i ran the following local dimming test which uses the white square and circle moving around a black screen and was surprised to see that the smaller the little white square/circle became the darker it appeared - the smallest becoming almost grey in colour (square shape affected the most).

Link to the local dimming test i used - would be interested in other Q70R results - especially the Samsung QE55Q70R .


I also noticed that the direction the leading edge of the shape moved in, it would become darker than the rest of shape as it moved around the screen - and as the shape became smaller it looked as though is was moving in and out of shadow.

And lastly as the image begins to speed up the image becomes blurry (expected) but seems excessive with the above issues added to the equation.

Question is - is this norma? As I've been reading a lot today about FALD and black crushing - and now i'm confused as to what i'm supposed to expect. But no mention of this issue - that i've come across yet...

*The TV is calibrated via a combination of main pro review recommended settings and personal preference - but having little affect regarding this issue. And all other colour calibration tests seem normal, great even - to my eyes.
That test appears to do the same with the leading edge on my tablet. Have you tried these settings Samsung Q70/Q70R QLED Calibration Settings
 

furryhobnob

Distinguished Member
It's Samsungs over aggressive algorithm to help mitigate blooming, there's not much you can do to stop it unfortunately.
And just for reference copying someone else's settings isn't calibrating your tv, it's just changing your settings.
 

bluin

Member
I get the same on my Q90r. 😞
Apologies - I didn't mean to spread my misery. Is it exactly the same?

I have another video below but you may not want to add to your woes.

It's Samsungs over aggressive algorithm to help mitigate blooming, there's not much you can do to stop it unfortunately.
Oh dear - i only read about blooming issues and brief remarks on over zealous Local Dimming.

The picture is great on the whole but i've yet to watch a really dark film (i.e. Gravity) - but when i watched the below 4K test even the fireworks were muted in colour - no where near as vibrant as my spare laptop. Is this still consistent with an over zealous software engineer or may i have a problem in addition to Samsung's aggressive algorithm?


And just for reference copying someone else's settings isn't calibrating your tv, it's just changing your settings.
True - but i ditched mine for generic testing (although only minor differences) as I wanted to rule out my setup as possible cause. Testing on defaults at times too - no difference.
 

furryhobnob

Distinguished Member
Apologies - I didn't mean to spread my misery. Is it exactly the same?

I have another video below but you may not want to add to your woes.


Oh dear - i only read about blooming issues and brief remarks on over zealous Local Dimming.

The picture is great on the whole but i've yet to watch a really dark film (i.e. Gravity) - but when i watched the below 4K test even the fireworks were muted in colour - no where near as vibrant as my spare laptop. Is this still consistent with an over zealous software engineer or may i have a problem in addition to Samsung's aggressive algorithm?



True - but i ditched mine for generic testing (although only minor differences) as I wanted to rule out my setup as possible cause. Testing on defaults at times too - no difference.
It was the same on their Q9fn last year, it muted bright highlights in favour of eliminating blooming in dark scenes, there's nothing you can do to change this other than try and get Samsung to change their dimming algorithm.
 

bluin

Member
It was the same on their Q9fn last year, it muted bright highlights in favour of eliminating blooming in dark scenes, there's nothing you can do to change this other than try and get Samsung to change their dimming algorithm.
Thanks again for your insights, @furryhobnob - there's some solace in knowing i have a 'normal' panel and the picture for average viewing is excellent. Had i not got spooked by some dimmed text, I would have been none-the-wiser - ignorance would have been bliss in this instance.

Plus, I can't honestly say which foible i would prefer - blooming or crushed blacks. I do know that my young kids (and wife) would have tested the burn limit in the OLEDs...
 

zeppelino

Distinguished Member
I think you’re worrying too much about very specific tests - pick your favourite movie and stick it on; if you don’t notice any issues then just enjoy your tv.

Beyond Oled there’s not much that will better your tv.
 

bluin

Member
I think you’re worrying too much about very specific tests - pick your favourite movie and stick it on; if you don’t notice any issues then just enjoy your tv.
Sound advice, and one I was adhering to as you'll find fault with any panel if you look hard enough.

I was using the tests originally for calibration purposes and then became disillusioned with the 4k firework vid. But, from responses it seems this is the norm and although TVs have moved on they"re still not able to cater for all.

I'll stick on Deadpool tomorrow night, crack a few beers, stop tweaking and see how it performs. I know the film well so should have little difficulty noticing if it's struggling with normal picture (rather than a panel stress test).
 

garlandjon

Standard Member
Would be nice to have the option to turn off the local dimming. Doesn't seem to do it in Game mode on my TV. I've not noticed the blooming issue either with it off.
 

bluin

Member
Would be nice to have the option to turn off the local dimming. Doesn't seem to do it in Game mode on my TV. I've not noticed the blooming issue either with it off.
Yes, it seems an odd decision to remove the ability to turn it off. Purely so the user can pick and choose their preference depending on what source they're viewing. Perhaps they were concerned users would see Local Dimming as a fault when compared to some pictures with it switched off...

The lady i spoke to at Samsung flagged it as a fault but, as mentioned, it was clear that she was reading from a crib sheet and suggested nothing that i hadn't tried already. Unsure why they're not prepared/trained to say that this is within tolerance and instead suggest/risk me returning the screen - especially as i relayed the info pretty much as outlined on the forum. I would have thought such a well known phenomenon would have filtered down to their support staff i.e. have a placating statement - weird.

Still tweaking - and will watch a blu-ray tonight.
 

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