Develop Bugs

Amoled black isn't as black as we thought?

I've found out, that the Amoled can't display perfect black. I tried the desktop clock thing, the blackle Google page (scrolled to black only area), and I made a photo in PhotoShop completely black and open it up in gallery.
What I noticed is, that the screen still is displaying something when it should be black. This is very easy to see if you put the phone to sleep when displaying such black.
What am I missing? Doesn't the Amoled completely turn of a pixel that is black? Can someone try to replicate this?
Do you think it's possible that I have an lcd desire and just don't know it?
Sent from my HTC Desire

I have also a Hero (with lcd display) and black on my Desire is "more black" than Hero's
For me it's ok

If you look at LCD screens through a circular polarisation filter you'll sometimes see coloured patterns on it, or it will get completely filtered out at a certain angle. To the best of my knowledge, OLEDs don't emit polarised light, so if you've been to see Avatar or another movie in Real3D and walked away with the glasses then you can use them as an LCD detector...
(The blacking out effect works as a cool CSI-esque monitor dust detector)

No disrespect, but... who cares???
So the blacks are not as deep as say, a Kuro plasma. This is a smartphone, not a home theater tv.

Jaa-Yoo said:
No disrespect, but... who cares???
So the blacks are not as deep as say, a Kuro plasma. This is a smartphone, not a home theater tv.
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no disrespect but,...
well real black "off pixel" don't use power so all the people who care about batterylife might care...
s.

I don't think they do emit light on blacks. I have noticed that in a completely dark room I can't see blacks on my Desire at all, it emits no visual light. Maybe the black you were testing isn't pure black.
Sent from my HTC Desire

"It's like, how much more black could this be? And the answer is none. None more black."
Couldn't help myself
Sent from my HTC Desire using XDA App

I do agree that it is much better than any lcd. BUT black should be no light at all. When you turn off the screen when all the pixels are supposed to be off, you see a change. You can also see the outline of the screen when it is in any of the previously mentioned methods of darkness.
Sent from my HTC Desire

I did the following test :
- found a room where I could be in complete darkness
- used the following enclosed file (a pure RGB=(0,0,0) 800x480 png file) and displayed it fullscreen on my phone.
- use the palm of a hand to cover the 4 lit buttons
- the screen is pretty damn BLACK ! (an LCD screen, next to it, also displaying black pixels, would look like a torchlight)
- After a minute or so, the eyes getting used to the darkness, I could very slightly see the screen. I don't know how the phone is built, but I'm guessing it's a light "leak" coming from the LED(s) of the 4 buttons.
I tried this procedure at various brightness settings (from min to max) : the remaining light coming from the screen did not change.
Is there a mod to kill the buttons backlight ?

It is possible to kill the backlights, but have not tried it myself.
http://forum.xda-developers.com/showthread.php?t=704977&highlight=buttons+backlight

Ok, switched off the buttons backlight thx to Flaggie. The screen indeed still emits some light when displaying a full screen black picture. Strange.
It would be interesting to get an explanation from HTC about this, but i'm pretty sure it pointless hoping they would reply to such a question. I'll give it a try...

Perhaps you hae one of those new Desire models with a LCD screen?

No, I bought it the day it came out. Try out on your own. The test I detailed is pretty straight forward...

kekkle said:
Perhaps you hae one of those new Desire models with a LCD screen?
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That is what I thought at first, but than the amount of light on dark would change when you change the brightness.
I want to know what HTC has to say about this.
PS: I bought my phone in June.
Sent from my HTC Desire

OMG does any of you know how a led screen works? lol Active Matrix Organic Light Emitting Diode its name clearly states that the pixels are self-illuminating so clearly unless the screen is of the display is always going to give some light off

It is actually the other way around. They are self emitting, they can turn off. LCDs, however have a backlight, which doesn't turn off, so some light still passes through.
Sent from my HTC Desire

OLED can havae infinate contrast ratios. I have a cowon s9, it has an OLED screen and in a pitch black room you cannot tell it's on. The desire does emit some light even on true black :-/

AndroHero said:
OMG does any of you know how a led screen works? lol Active Matrix Organic Light Emitting Diode its name clearly states that the pixels are self-illuminating so clearly unless the screen is of the display is always going to give some light off
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OMG please read the Wikipedia article...

Unlike over saturated colors and Pentile jagginess which are clearly visible and to some point distracting (at least to me) this seem like pure academic issue, since it can be visible only in total darkness and even then it is not visible unless screen is completely black.
What would be practical purpose in looking at black screen in darkness?

vlasac said:
Unlike over saturated colors and Pentile jagginess which are clearly visible and to some point distracting (at least to me) this seem like pure academic issue, since it can be visible only in total darkness and even then it is not visible unless screen is completely black.
What would be practical purpose in looking at black screen in darkness?
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I agree. This is an academic issue, but aren't you a bit disturbed by the fact that there has been soo much talk about this oled screen and its pure black, and it was all a lie?
I think the problem might be in the image to screen processing where it gets converted to the pentile matrix(and over saturated).
Sent from my HTC Desire

Blue-green tint

Hey xda forum!
I just bought the awesome phone, desire, but i noticed that my screen is blue-greenish tint, compared to my friends Desire. I think i can live with it, but is there anything to do? i've searched for this problem and found that the samsung vibrant also has this problem.
what can i do, is there any way u can change the setting of ur display? turning brightness up helps, but outside, my friends desire is easier to see/read compared to mine.

You may have it set so that brightness is Auto,
Settings > Display > Brightness

It was set to auto but that really look awful
So it is on full brightness now
Sent from my HTC Desire using XDA App

ninjaijutsu said:
It was set to auto but that really look awful
So it is on full brightness now
Sent from my HTC Desire using XDA App
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the amoled screen does have a blue tint, from what i beleve blue led's die out really quickly, Samsung on purpose made the screen to over display blue, and as time goes on, the blue will die to a yellow. So if your phone is more blue today, it will last longer tomorrow. also Samsung tunes all of their displays (TVs and all) towards the bluer end of the spectrum because it gives the display a higher apparent brightness because our eyes perceive bluish white as being brighter than yellowish white even with no actual brightness difference.

AndroHero said:
the amoled screen does have a blue tint, from what i beleve blue led's die out really quickly, Samsung on purpose made the screen to over display blue, and as time goes on, the blue will die to a yellow. So if your phone is more blue today, it will last longer tomorrow. also Samsung tunes all of their displays (TVs and all) towards the bluer end of the spectrum because it gives the display a higher apparent brightness because our eyes perceive bluish white as being brighter than yellowish white even with no actual brightness difference.
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thanks for the info, that actually good news followed up on ur info and read about it on wiki.
i guess thats the only way they can expand the life time of old amoled displays.
back to auto brightness

I just bought my desire and have same problem ad u guys. I accepted the fact that blue had a low lifespan, but was still trying to hunt for a solution. After dl many brightness apps I found, Brightness profiles. I started playing around to change the brightness and notice some weird flickness. Example at 74 % it was more "yellow" than on 75%. At 96 % had less blue tint than 100 %. I could see it clear under no light before I went to sleep. So I guess they are defect but Ye, that's my workaround cuz I'm too lazy to return the phone and I like the cool tint now, or well it got better

[Q] Black color theme vs others

Since screen consumes a good chunk of the total battery percentage, I've been reading some things on the internet and it seems like people are saying black color theme consumes less battery power than other colored themes, but only on a certain type of LED. If so, does the MT3GS has that type of screen and does black color theme really saves more battery for our phone?
some other odd stuff: first one is what happens when i leave my phone on in a lecture hall for an hour... second one is just my screen going weird.

That is for AMOLED screens and you have to use a mod that uses true blacks and what that is, is instead of using backlit blacks it just doesn't use those pixels and so that increases battery life. (And AMOLED is used on higher end devices so no the MT3GS doesn't have it.)
Sent from my T-Mobile myTouch 3G Slide using XDA Premium App

Ah, thanks very much!

This phone doesn't need inverted / black ?

Having used so many Samsung phones with AMOLED screens, it was always recommended to use black apps, and dark wallpapers to save battery life, that white is a big battery drain on AMOLED.
Now with the One X being S-LCD2, I thought we don't need to use black as much ? Is white apps, and lighter wallpapers OK on this phone ? White is not a battery drain on the One X ?
Sent from my HTC One X using xda premium

No, it's backlit, which is why it's brighter.

AMOLED can turn off the pixels that need to be black, saving power. LCD, on the other hand, can not.
The One X has an LCD screen, so there's no advantage of more black. Exactly the same amount of power being used, regardless of the colour shown.

peedub said:
AMOLED can turn off the pixels that need to be black, saving power. LCD, on the other hand, can not.
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That's not a clear description.
With OLED, the pixels emit light, on black, they emit no light and require no power.
With LCD, the pixels block light (either reflected or backlit), the backlight is always on, always requiring power.
There are many other aspects, such as contrast, brightness, colour gamut, aging effects etc.

did you notice that the WHITE calibration is "too much" warm?

i can clearly see that the white of this phone is much much more warm and yellowish respecting others phones with lcf, but also a galaxy note 4 ( amoled) of one of my friends.
i can't understand why lenovo made this calibration. Of course maybe using it as primary phone you will not notice it after some days, but at the moment it is my secondary phone and every time i switch from lcd to p2's amoled i can clearly see that the white ruins all the colors....into an image.
ps: maybe OVER 50% of brightness the white starts to be "ok..." but under 50... 40% it is not a nice white

realista87 said:
i can clearly see that the white of this phone is much much more warm and yellowish respecting others phones with lcf, but also a galaxy note 4 ( amoled) of one of my friends.
i can't understand why lenovo made this calibration. Of course maybe using it as primary phone you will not notice it after some days, but at the moment it is my secondary phone and every time i switch from lcd to p2's amoled i can clearly see that the white ruins all the colors....into an image.
ps: maybe OVER 50% of brightness the white starts to be "ok..." but under 50... 40% it is not a nice white
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Ya it is too warm on stock but now i m using custom rom so i can set cool/warn colors
Sent from my Lenovo P2 using XDA Labs

which rom? do you use kernel adiutor to set the rgb values?

realista87 said:
which rom? do you use kernel adiutor to set the rgb values?
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Aicp rom,,i use in built live display
Sent from my Lenovo P2 using XDA Labs

ALISTON PRINCE FERNANDEZ said:
Aicp rom,,i use in built live display
Sent from my Lenovo P2 using XDA Labs
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but does it interfere with the PURE BLACK? i noticed that there are apps that can "fix" the temperature of the color by adding a LAYER on the screen....
but this layer corrupts the true black.... no more really black but with a tint of blue or yellow ( blue if you try to make colder, yellof if warmer)
i hope you made a real test about it, use the app https://play.google.com/store/apps/details?id=com.gombosdev.displaytester and visualize the BLACK color.
if it is not 100% off the display..... the live display option of your rom is not acceptable

realista87 said:
but does it interfere with the PURE BLACK? i noticed that there are apps that can "fix" the temperature of the color by adding a LAYER on the screen....
but this layer corrupts the true black.... no more really black but with a tint of blue or yellow ( blue if you try to make colder, yellof if warmer)
i hope you made a real test about it, use the app https://play.google.com/store/apps/details?id=com.gombosdev.displaytester and visualize the BLACK color.
if it is not 100% off the display..... the live display option of your rom is not acceptable
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Nup,,black are true blacks(pure black pixels get off),,almoled display does not have pure white they are warm(yellowish)i had set it to cool color (blue)which makes the screen look little white than yellow,,i will compare display with samsung device and check,,buh black are still pure black no yellowish or white tint on black
Sorry for bad English
Sent from my Lenovo P2 using XDA Labs

but did u test? because some tricks to change the temperature of the displays.... are to add a "layer" of color.... and this makes NO MORE TRUE BLACKS on amoled diplays....

Yes,there is noticable difference in white the stock ROM now looks a little yellow but the stock deodexed version has the cool white colour which looks far more beeter that yellowish tint
I have not so idea for the reason behind that may be Lenovo has recalibrated the screen if you want to change the tint you can try various apps that requires root to calibrate screen Colors manually

i found the problem !!!
go in the live display and at the colour calibration menu.
JUST set the green color to 92% and the white will be PERFECT
i noticed tha tis ONLY THE GREEN that destroys the white.... just lowering it to 95 gives a normal warmish white... setting to 90 it is like a normal lcd cold white ... at 92 it is perfect between a warm and cold yellow, the perfect sweet spot.
now i am FINALLY HAPPY with my screen.... and the white written on all the app themed with black substratum, are finally well constrasted with the black..... being pure white