Local dimming not working from 4K HDR bluray source

[TobyCG]

Anyone else noticed this?

When I play a 4K HDR bluray, the local dimming doesn't work.  The setting is locked at Medium and can't be changed but it's patently not working.

Yes I know the backlight is driven to max in HDR mode but there's no reason local dimming shouldn't still work.

If the entire image goes black (such as after logos etc at the beginning of a film) then the dimming kicks in and the screen fades to perfect black but, if there's anything anywhere on the screen at all, the brightness level goes up across the whole screen, as if local dimming was disabled.

Oddly I only notice this from a 4K HDR bluray source, if I play 4K HDR content from Amazon Prime (such as The Grand Tour for example), dimming works fine.

This is clearly a bug and I've reported it to Sony but, as usual, their support is atrocious and they seem totally disinterested.

[TobyCG]

Have now proven conclusively that local dimming is not working from a 4K HDR Bluray source.

Started playing The Martian and then paused it just after the studio logos on a totally black frame.  TV turns the backlight right down and it appear perfect black - all ok.

Now bring up the player's info overlay at the top of the screen (playback stats etc) and you'd expect the backlight at the top of the screen only to come on but no, the backlight comes up on the whole screen.  Toggle the overlay off again and the screen dims in entirety.  Conclusive proof there's no local dimming.

If I try exactly the same test with a normal Bluray from the same player, it behaves as it should with the backlight at the top of the screen only coming on.

Have reported this to Sony.  Big question is whether it's a general issue or specific to me.

[TobyCG]

Well I found the solution but no one here nor at Sony seems to give a toss about such things so I'll keep it to myself.

[Anonymous]

Hi there

My first thought was to reply with a message of 'great attitude' - however this is not fair on you.  The reason I say this is because you may not be aware of the fact that Sony do not generally reply to comments/questions on these forums.  They sometimes do monitor 'key' threads for when there is a large issue - but as a whole it is up us, the Community to help each other.

The issue you raised with Local Dimming not working from a 4K Bluray source is quite a specific issue that relates to specific models of TV (which unfortunately did not mention a model number) to a 4K HDR bluray player.  As 4K bluray players rather new on the market, my assumption is that not many people would have a 4K HDR Bluray player and hence unlikely to be able to help you due to not having the same or similar equipment setup as you.

I unfortunately never saw your post until now, however even if I did, I wouldnt know where to start in regards to helping you - so my response would have been to escalate your issue to Sony Support - which you had already contacted Sony anyhow.

Anyway, I am glad you have managed to solve the issue - it is your choice whether to post the solution, but the whole idea of this community is to help each other if we can.

Thank you.

[TobyCG]

I appreciate that Sony don't generally monitor these forums.

My annoyance is due to Sony's total lack of any support on this issue, or indeed others I've raised with them.  They reply with sporadic emails, if at all, usually just repeating the same old advice to try a factory reset.

With regards to this particular issue, I managed to record a video of the issue which I uploaded to Youtube and forwarded a link to Sony support.  I did the same with another issue I'm experiencing.  Not only did they not even reply to my communications, the videos went un-watched.

I've always bought Sony TVs but I've had enough and won't buy another.  The lack of support is totally unacceptable and not what I expect from any manufacturer when spending this kind of money, let alone a brand as big as Sony.

Anyway, for the benefit of anyone else experiencing this issue or who wants to experiment, the resolution lied in the MotionFlow settings.  It transpires that, with MotionFlow disabled, local dimming doesn't work at all with an HDR source.  Enabling MotionFlow corrects the problem.  It could well be that it's not just HDR sources but merely that MotionFlow was disabled on the HDMI socket my Bluray player was connected to but only for HDR Video, not for SDR material (settings are stored separately of course).

[Anonymous]

Hi there

I fully understand your frustrations on this and I am aware that Sony Support 'seemingly ignores' communications on more complex issues. I also find this unacceptable too, however if you dont mind, I would like to raise this with Sony, using your complaint on this thread.  If that is ok, can you please post here, or private message me the Case ID numbers for the issues that you have had poor experience of support.

Also, thanks for posting the solution - I am sure it will help others.  Interesting the connection between motionflow and local dimming in regards to HDR.

Cheers

[TobyCG]

I'll have to sort them all into a coherent list - I ended up with several support issues pertaining to different issues then, after receiving virtually no support, tried submitting a summary of all the problems I'd had.

Now I've ended up with at least three separate case numbers and multiple representatives dealing (or rather not dealing) with them.

I'll compile it all into a proper timeline when I get a chance.

[Anonymous]

Cool - sounds a nightmare !!

[royabrown]

It would also be very useful if you could indicate which model of TV and which make and model of 4K Bluray player (almost certainly not Sony!) you are experiencing this issue with, for the benefit of those later adopters who follow in your footsteps.

Me, I'm waiting for Planet Earth II to be available on 4K Bluray (Edit: 13 March it seems) before I put my toe in that particular water 🙂

[TobyCG]

It's an XD93 with a Panasonic DMP-UB900 player, although the player is irrelevant.

I have PE2 on pre-order.