[steven123]

I have recently purchased a new 4K/UHD TV. The TV is a Digihome 55", model: 55304UHDSM. As a budget (I believe vestal based) set there is unfortunately barely any info online about it so I don't know if the issue I have is common on these. Anyway, while I am generally really pleased with it in terms of general colour, detail and overall PQ, the set does seem to suffer from fairly noticeable backlight leakage or bleed at the four corners of the panel.

I wouldn't say it is terribly noticeable generally and not obvious at all on lighter scenes, but on scenes where much of the image is dark/black the four corners do appear noticeably lighter and on such scenes once you have seen the issue you unfortunately cannot easily un-see it.

Anyway, the purpose of this thread is partly to determine how retailers view backlight bleed, is it considered as a defect and thus the set can be swapped for a replacement? However, assuming the retailer (Coop Electrical) does agree there is a defect, what are the chances of a replacement having exactly the same issue? As I’m sure once can appreciate a 55” TV requires a fair bit of work to repackage and reinstall the new one and it would be incredibly annoying if the replacement did the exact same thing.

Might I be better trying to get a partial refund for the issue and just accepting that this model of TV is going to have some degree of backlight bleed regardless?

Finally, are there any actions I could take myself to minimise the visibility of backlight bleed? Is the amount of bleed related to the backlight level? E.g. if I used say a backlight level of 50% instead of the current 100% would the reduced light intensity hide the bleed?

As always, any advice greatly appreciated.

[Stig]

How long have you had it, and how did you order it? E.g. online?

[Chris Frost]

Backlight bleed is one of the (many) trade-offs made to get thinner, larger and ever-cheaper tellies. You'll find more of it as screen size increases and price decreases.

As you've noted yourself, Digihome is a Vestel. That company makes budget TVs, and budget TVs suffer more from this problem because there's less money in the pot for a rigid chassis and the sort of casework that could help reduce the issue. That said, I've seen backlight bleed on some very expensive sets too, so you're unlikely to eliminate it completely even on TVs over £1000.

The next move is up to you. I think you're going to have a very hard time finding a 55" Digihome without some level of backlight bleed. I'm also doubtful that swapping the TV is going to significantly improve the issue unless the TV is obviously broken in some way. This is a budget set when all is said and done. Viewing any TV under the bright lights of a store display will mask all but the worst cases of backlight bleed. It only becomes apparent under subdued lighting. If you decide to change brand or up the budget then you still might find that any replacement set has similar issues. This is a really common thing.

Price carries through to the next point; some kind of partial refund. In a sense you've already had that in the purchase price of the TV. This is a really big screen 4K TV for around £500. IOW you've paid a low price for the technology and screen size, so whether you realised it or not at the time of purchase this is one of the compromises you have accepted to get a 55" 4K TV for under £500.

Minimising the backlight setting will help. It will also extend the TVs life as backlight failure from being over-driven does appear to be a common fault in a lot of TVs. Also make sure to watch with some room light on. That way the problem won't be as noticeable.

[steven123]

Quote:

Originally Posted by Stig

How long have you had it, and how did you order it? E.g. online?

Yes, it was purchased online at Coop Electrical shop, direct link here: http://www.coopelectricalshop.co.uk/...-55304UHDSM-BK

Got it about a week and a half ago.

[Stig]

Quote:

Originally Posted by steven123

Yes, it was purchased online at Coop Electrical shop, direct link here: http://www.coopelectricalshop.co.uk/...-55304UHDSM-BK

Got it about a week and a half ago.

I refer you to their returns policy,
http://www.coopelectricalshop.co.uk/...turns/#returns

As the comment above, you get what you pay for, and backlight bleed is a problem on cheaper TVs.

[steven123]

Quote:

Originally Posted by Chris Frost

Backlight bleed is one of the (many) trade-offs made to get thinner, larger and ever-cheaper tellies. You'll find more of it as screen size increases and price decreases.

As you've noted yourself, Digihome is a Vestel. That company makes budget TVs, and budget TVs suffer more from this problem because there's less money in the pot for a rigid chassis and the sort of casework that could help reduce the issue. That said, I've seen backlight bleed on some very expensive sets too, so you're unlikely to eliminate it completely even on TVs over £1000.

The next move is up to you. I think you're going to have a very hard time finding a 55" Digihome without some level of backlight bleed. I'm also doubtful that swapping the TV is going to significantly improve the issue unless the TV is obviously broken in some way. This is a budget set when all is said and done. Viewing any TV under the bright lights of a store display will mask all but the worst cases of backlight bleed. It only becomes apparent under subdued lighting. If you decide to change brand or up the budget then you still might find that any replacement set has similar issues. This is a really common thing.

Price carries through to the next point; some kind of partial refund. In a sense you've already had that in the purchase price of the TV. This is a really big screen 4K TV for around £500. IOW you've paid a low price for the technology and screen size, so whether you realised it or not at the time of purchase this is one of the compromises you have accepted to get a 55" 4K TV for under £500.

Minimising the backlight setting will help. It will also extend the TVs life as backlight failure from being over-driven does appear to be a common fault in a lot of TVs. Also make sure to watch with some room light on. That way the problem won't be as noticeable.

Thanks for the info. Yes, as you noted I do realise Digihome is very much at the budget end, and I did pretty well with the price, which was only £350 when I bought it, so a huge amount of TV for the money to be fair. My aim in buying it was to both get a larger screen so it would be naturally more immersive than my previous set and join the 4K generation, which in itself benefits from screen size. My last two TVs were LGs and whilst I do like LG sets generally, I'm not especially brand loyal and if I had stuck with LG (or another big brand) I would be paying a lot more for a smaller set. Aside from that, current LG 4K sets don't even have true 4K thanks to the whole white pixel issue, amazed how they got away with that as I’d be furious if I’d bought one of those, but I digress.

In my older LG sets favour, neither of them had any backlight bleed or if they did it was minor enough I couldn’t detect it. One thing I do notice looking between my last LG (about 5 years old) and the Digihome is just how much thinner the bezel around the screen is on the Digihome. It barely has one, it is just a few millimetres all around, slightly wider on the base, and while it makes the set look smarter and more modern than the LG, I wonder if this partly contributes to the issue? As with such as small bezel they probably don’t have enough room to adequately block the backlight leakage.

Anyway, from what you say I’m pretty sure I won’t push the retailer for a return or swap as I don’t want to waste both our time with a problem another TV is just as likely to have. I haven’t decided fully yet but I might just mention the problem to them and see if they want to do anything about it, but if they suggest a return I would probably decline as I don’t think it’s that serious really and aside from the backlight bleed the TV has actually comfortably exceeded my expectations for what it cost.

[GDK]

I'm curious as what you mean by the "white pixel issue"?

A few months ago I replaced my 10 year old Sony LCD TV with an LG, OLED 4K HDR TV and I haven't noticed any problems.

If you're referring to the maximum brightness for OLED displays not being as bright as LCD displays...

While that's perfectly true I've found it doesn't make any practical difference. It's perfectly bright enough for normal viewing in a normal, brightly lit lounge. When watching in ideal conditions you see the benefit of OLED's perfect blacks over LCD's dark greys (due to light leakage which is inherent with LCD and which all LCD displays suffer from to one degree or another).

I watch news and other casual viewing in a brightly lit lounge.

For critical viewing, especially HDR material, I prefer to watch in cinema-like conditions, i.e. near total darkness. For me, the perfect blacks of OLED displays trumps the brighter peak brightness of LCD screens.

Both types of screen meet the specs for UHD Premium. Both types of screen are a compromise (best available) as neither can meet the specs for "true" HDR. Currently no screen can claim to be HDR in the fullest sense and match the dynamic range the human eye is capable of.

[treefr0g]

Do you have 'Dynamic Backlight' and if so, is it switched on?

The only time I see light bleed on my TV is when watching 3D movies (in dark scenes and especially if they have black lines at top and bottom).

The combination of the lights in the room being switched off and the fact that the TV automatically switches dynamic backlight off and backlight intensity to maximum causes all 4 corners to light up.

Normally I have the 'Dynamic backlight' set to normal, the backlight set at about 60% and powersaving on and I have no problem at all (even in the dark).

[Chris Frost]

Quote:

Originally Posted by steven123

Aside from that, current LG 4K sets don't even have true 4K thanks to the whole white pixel issue, amazed how they got away with that as I’d be furious if I’d bought one of those, but I digress.

I too am curious what you mean about "white pixels" and not being true 4K.

[Tassium]

Here's a 55" 4k TV for £1000 that has quite bad backlite bleed in the corners.

https://www.amazon.co.uk/LG-55-Ultra...keywords=lg+tv

(scroll down to the reviews)

[GDK]

Quote:

Originally Posted by Tassium

Here's a 55" 4k TV for £1000 that has quite bad backlite bleed in the corners.

https://www.amazon.co.uk/LG-55-Ultra...keywords=lg+tv

(scroll down to the reviews)

Yep. It's an LCD (LED backlight) display, not an OLED display.

[chrisjr]

Quote:

Originally Posted by GDK

I'm curious as what you mean by the "white pixel issue"?

Quote:

Originally Posted by Chris Frost

I too am curious what you mean about "white pixels" and not being true 4K.

Could it be this?

http://hdguru.com/new-lg-rgbw-4k-ult...sparks-debate/

[steven123]

Quote:

Originally Posted by chrisjr

Could it be this?

http://hdguru.com/new-lg-rgbw-4k-ult...sparks-debate/

Yes, that is it. Though the article I initially read on it was a lot more damning of the technology than that but I'm struggling to find it again now. Effectively they say that in certain circumstances the RGBW pixel structure (essentially the extra white pixel) reduces the effective screen resolution in certain circumstances so you aren't getting the full UHD resolution.

[steven123]

Quote:

Originally Posted by treefr0g

Do you have 'Dynamic Backlight' and if so, is it switched on?

The only time I see light bleed on my TV is when watching 3D movies (in dark scenes and especially if they have black lines at top and bottom).

The combination of the lights in the room being switched off and the fact that the TV automatically switches dynamic backlight off and backlight intensity to maximum causes all 4 corners to light up.

Normally I have the 'Dynamic backlight' set to normal, the backlight set at about 60% and powersaving on and I have no problem at all (even in the dark).

I don't have dynamic backlight but it does have dynamic contrast but i always keep that to low or more usually off. There are a few other things like energy saving, which is off and noise reduction, which I keep off as it is pointless with digital signals anyway.

One area, where it differs from my previous LG is that you cannot directly alter the backlight setting, it is greyed out and set to 100% on most presets e.g. dynamic, game, sports. The only one that reduces it is the natural setting, which puts it at 50%.

[GDK]

Quote:

Originally Posted by chrisjr

Could it be this?

http://hdguru.com/new-lg-rgbw-4k-ult...sparks-debate/

Ah. I hadn't heard about that. Is it a "cheat" or a "valid improvement"? Does it mean the TV is no longer 4K?

I have to say I'm not sure.

At any rate, it only applies to that one range of LCD (LED backlight) TVs in LG's range. It doesn't apply to their OLED TVs.

[Tassium]

So the white pixel issue is an LCD technology that uses a fewer number of pixels overall, using clever technology to simulate 4k while really using a 3k panel.

A white pixel replaces a sub-pixel in each grouping:

RGWRWBWGB


There isn't an "extra" white pixel. White replaces a particular colour sub-pixel in each grouping, so 25% fewer subpixels across the screen.

Technology does clever stuff to make it seem the same as a true RGB sub-pixel panel.

[Stig]

Quote:

Originally Posted by Tassium

So the white pixel issue is an LCD technology that uses a fewer number of pixels overall, using clever technology to simulate 4k while really using a 3k panel.

A white pixel replaces a sub-pixel in each grouping:

RGWRWBWGB


There isn't an "extra" white pixel. White replaces a particular colour sub-pixel in each grouping, so 25% fewer subpixels across the screen.

Technology does clever stuff to make it seem the same as a true RGB sub-pixel panel.

Interesting, and I've done some more reading.

It's not so much a matter of resolution, but colour. Until recently we measured TVs by vertical resolution, e.g. 720p, 1080p. These LG sets are still 2160 vertical pixels like any other '4K' TV. What changes is the horizontal resolution, and the ability to display colour contrast.

https://www.youtube.com/watch?v=Rssh8FqMI_8

[Tassium]

I don't think there are 2160 vertical pixels either.

While there are 2160 layers, both horizontally and vertically it's using sub-pixels in the vicinity to create the pixel. So sub-pixels from two or more layers might be used.


In practice it probably looks fine for video material like films, but probably not recommended as a monitor.

[Chris Frost]

Quote:

Originally Posted by Tassium

So the white pixel issue is an LCD technology that uses a fewer number of pixels overall, using clever technology to simulate 4k while really using a 3k panel.

A white pixel replaces a sub-pixel in each grouping:

RGWRWBWGB


There isn't an "extra" white pixel. White replaces a particular colour sub-pixel in each grouping, so 25% fewer subpixels across the screen.

Technology does clever stuff to make it seem the same as a true RGB sub-pixel panel.

I think there's some very odd interpretations of resolution going on.

We know about sub-pixels and that in a basic RGB arrangement there are three sub-pixels for each of the 3840x2160 pixel positions on the screen. Replacing one sub pixel per pixel position doesn't change the total number of sub-pixels. All it does is change the proportion of red green and blue by adding white ti the mix. It's still a 4k (UHD to be precise) resolution set, but with a 33.333% reduction in the amount of red green and blue subpixels on screen. That deficit is then filled by white replacing R G or B. However, what that does to the colour balance of the TV is a different thing altogether.

The idea of RGBW has been used in business DLP projectors for quite a while. The implementation is slightly different, but the aim of improved light output at the expense of colour fidelity seems to me to be what LG want for their TVs . It's interesting that with home cinema DLP projectors they dump the RGBW colour wheel and use RGB instead to get better colour saturation and a more accurate colour gamut.

[treefr0g]

Quote:

Originally Posted by steven123

I don't have dynamic backlight but it does have dynamic contrast but i always keep that to low or more usually off. There are a few other things like energy saving, which is off and noise reduction, which I keep off as it is pointless with digital signals anyway.

One area, where it differs from my previous LG is that you cannot directly alter the backlight setting, it is greyed out and set to 100% on most presets e.g. dynamic, game, sports. The only one that reduces it is the natural setting, which puts it at 50%.

Have you tried turning the power saver on? If it's like mine then this will reduce the backlight.

Dynamic contrast was the first thing that I turned off on my TV. It's just plain weird.

[Tassium]

Apparently my understanding is incorrect.

http://www.hdtvtest.co.uk/news/rgbw-201510084189.htm


BGRWBGRWBGRWBGRW
RWBGRWBGRWBGRW


Regardless of the details there are fewer sub-pixels in these panels. It's about cutting costs.

[steven123]

I actually contacted the store about the backlight bleed to see what they suggested. I included a description and some photos. Unfortunately, they seem determined that it is a fault with the set and want to replace it for me, though as none are currently in stock I have to wait until some more become available and then swap it or else return it for a refund, which definitely isn't happening.

They would not consider any possibility of partial refund, store credit, or anything other than return for refund or replacement, which just seems very inflexible and total overkill for what is really a fairly minor issue IMHO. No idea why they are so keen for a return, surely sending specialist large item couriers back and forward over a minor backlight issue is a massive waste of money for them?

[GDK]

Quote:

Originally Posted by Tassium

Apparently my understanding is incorrect.

http://www.hdtvtest.co.uk/news/rgbw-201510084189.htm


BGRWBGRWBGRWBGRW
RWBGRWBGRWBGRW


Regardless of the details there are fewer sub-pixels in these panels. It's about cutting costs.

Agreed. It's very telling that this "feature" is for low end, or budget TVs in LG's range.

[Nigel Goodwin]

Quote:

Originally Posted by steven123

They would not consider any possibility of partial refund, store credit, or anything other than return for refund or replacement, which just seems very inflexible and total overkill for what is really a fairly minor issue IMHO.

Why should they do anything else?, as it is there's nothing wrong with the TV anyway, it's almost certainly operating entirely within it's design specifications - you yourself even call it a 'minor issue'.

So basically you've bought the cheapest set you could find, discovered it's not as good as one three times the prices, and now want them to give you a even cheaper price on the set?.

The retailer is there to (try and) make money, there's almost no profit made selling a TV (particularly one as cheap as this), if they give you a partial refund then they are probably losing money.

[steven123]

Quote:

Originally Posted by Nigel Goodwin

Why should they do anything else?, as it is there's nothing wrong with the TV anyway, it's almost certainly operating entirely within it's design specifications - you yourself even call it a 'minor issue'.

So basically you've bought the cheapest set you could find, discovered it's not as good as one three times the prices, and now want them to give you a even cheaper price on the set?.

The retailer is there to (try and) make money, there's almost no profit made selling a TV (particularly one as cheap as this), if they give you a partial refund then they are probably losing money.

The main reason they should offer some other resolution is because returns, which I should add they are pushing me to do, not the other way around, are so wasteful (and costly) for minor issues like this. Having big vans driving potentially hundreds of miles wasting loads of petrol pumping out tonnes of CO2 for a tiny backlight issue, costing the retailer loads in the process, wasting the customers time having to repackage everything perfectly, then unpackage the new one, crazy for minor issues like this, yet that is exactly what THEY want me to do and through such advice probably hundreds happen all the time because of overly rigid policies like this.

How does paying extra collection/delivery fees to their couriers not to mention having to send the slightly faulty set back to the manufacturer help the retailer maintain their profits? by comparison a little bit of goodwill in a one off small partial refund or even just a credit against a future purchase (which I would have been equally happy with) to encourage repeat trade costs them virtually nothing in real terms, yet goes a long way with the customer so it’s puzzling why some retailers are stupidly adverse to offering them.

I have been looking to purchase a new washing machine this week after the last one broke and was looking at a pretty good model on their store, if they had made any offer to me at all, even as little as £10-15 off a future purchase, I would have got the washing machine with them too, giving them two big sales within as many weeks from me, but instead they lost a new sale through sticking to their policy too rigidly and not considering the customers preference.