Nexus screen tech - PenTile, dpi, SAMOLED

[sjael]

Guess it's a matter of semantics, as a one-bit monochrome display would satisfy the same requirements. Just seems to me if a test doesn't measure what people actually perceive, then it's not a useful test for measuring a device's suitability to be used by people.

So black and white displays don't have pixels? Afraid I can't agree there.

It's not really semantics. An 800x480 PenTile display displays an 800x480 image.

 

[AntimonyER]

Competing technologies tend to cause technology advances.

PenTile, qHD, RGB, 720p, LCD, SAMOLED, in the end it all comes down to two things -

This is Android, where choice is good.

Manufacturers are competing hard to give choices that people want - we win.

And with the GNex, Sammy/Google/Verizon have come the closest yet to making the perfect phone for me pentile is a little bit of a disappointment, but at 720p, I think I will be OK. Well have a full slate today, so probably will not get back til after 10k. Have fun!

 

[Ltgk20]

One thing which has been mentioned about pentile but probably needs more focus is its performance on bright light. I have a friend who picked up a bionic and he can see his screen well in full sunlight. Given the use of a phone as a gps in the car and use outside this seems relavent to me.

 

[TheRoosevelt]

There are two things to consider here. You create colors on a display like this by turn off/down certain sub-pixels. To create a solid black line, you turn off all the sub-pixels in an RGB stripe. In a PenTile display, however, you don't turn whole pixels off because the pixels don't have real physical coordinates.

Combined with the fact that, say, next to each other RGBG pixels still appear white (and not some super green white,) there will be instances where you end up making a black line by turning individual sub-pixels off. Where a hi-red, hi-green, low-blue color meets black, you will end up with something like (X means off/black) this:
XGRX
RGXX
XGRX
RGXX
Which results in a fuzzy edge.

If you then take a 2:1 ratio, it would look something like this:
XXGRRX
RRGXXX
XXGRRX
RRGXXX
Which makes the edge look even worse.

Of course there's a lot of 'magic' that goes into blending pixels together, but you get the basic idea.



RGBW actually gives the power savings. Because the white pixel doesn't affect colors, it effectively increases your brightness by 25% at the same backlight power. Unfortunately it also increases the distance between colored sub-pixels, making blending less effective, and thus harming color reproduction.

RGBG gives more accurate colors though.

Boy, am I glad you were there to take all the display questions after I left, because I'll tell ya, I'd reached the extent of my knowledge in that first post

Edit: You too, earlymon, thanks for that

 

[nj02vette]

I must be among the inordinately sensitive to this technology, as I can't look at a solid color or any sort of motion on these screens without seeing the effects of the PenTile. I guess it's not a deal breaker, but it is very noticeable and distracting for me. And I am a bit disappointed that I still see it in BruceWayne's video..assuming it will be a similar screen in the Nexus.

Screens that are photographed with a videocamera can be very deceptive. See it in person to make a determination.

 

[nj02vette]

OK. Power savings with PenTile - no.

Consider two screens at 720p, same size. Put up a solid red image on both. The rgb one will have 1/3 of its subpixels lit, the PenTile one will have only 1/4.

The only way for them to appear the same would be if the PenTile one increased brightness (increased power consumption) to compensate.

When I questioned the CEO and lead developer of the company that makes PenTile, she confirmed that, indeed, PenTile has a form of dynamic brightness control built in that is constantly making that adjustment.

Some color combinations will save power, others will use more, and in the end, it's a wash.

......

Excellent synopsis.

There is a diference between SAMOLED and LCD pentile, as LCD is more sensitive to power differences. SAMOLED, with no backlight, is completely dependant on the source material. It takes almost no power to run an all black screen, while LCD, there is always a backlight running (backlight is the single largest drain of LCD).

So it's very difficult to characterize actual power savings, because it all comes down to what they are displaying. If the test uses more blacks, AMOLED will show signifigant power savings, but if it has more whites, then it will be worse. As said, it's pretty much a wash.

 

[jimbo1mcm]

I need to know when the final exam will be on Pentile screens.( It will be multiple choice, so make sure you don't choose choice A. or D.)

 

[nj02vette]

Everyone keep in mind that engineering, like life, is all about compromises. This isn't Samsung's choice to put in a Pentile display. It's just reality.

I'm sure Samsung would have preferred to design a phone with a full 1080p display, 6GHz octocore processor, 20MP camera, and 1 month battery life.

But that technology doesn't exist. They have to use the processor that's available, camera optics that will fit in the package, and battery tech available.

In the case of the screen, Samsung is the premier manufacturer of organic LED technology. But they don't have the manufacturing technology to manufacture SAMOLED with that density yet in full RGB capacity. But they can print the displays in pentile.

Pentile is just a compromise, not a feature or advanced technology. Samsung isn't using it because they want to, they are using it because they have to. Next year, the tech may be available for full 1080p RGB SAMOLED+, but it's not available yet.

 

[nj02vette]

I need to know when the final exam will be on Pentile screens.( It will be multiple choice, so make sure you don't choose choice A. or D.)

Heaven forbid anyone learn anything.

I'm making all the answers A or D, and throw some true/false in there too.

 

[EarlyMon]

One thing which has been mentioned about pentile but probably needs more focus is its performance on bright light. I have a friend who picked up a bionic and he can see his screen well in full sunlight. Given the use of a phone as a gps in the car and use outside this seems relavent to me.

Maybe PenTile, maybe that in SAMOLED provided that - either way, that can be important to people.

Exactly why I say just pick what you like, and don't sweat the buzzwords or sales pitches.

 

[rushmore]

IMO, Pentile tech positives (power consumption, sharpness, outdoors clarity) outweigh the negatives (grain effect in some background and some color trailing), but just BARELY). The grain is not an issue to me on a small display, but the object trailing can be annoying, since some games (especially emulators) give off trail effects for some moving objects (especially red).

If newer pentile displays have no trail effect, I would be happy. That all said, an IPS panel like on the iPod 4 is still the best display tech and there should be more devices with the tech this time next year, or earlier (Hitachi is ramping up capacity of their own version).

 

[mongstradamus]

Holy cow i had to scroll through endless posts and pages on rgbg and pentile. Somebody needs to put up some gifs of not 1 dead horse being beaten but hundreds lol

My god that was more painful than the camera megapixel posts because it went on so darn long.

Start up a seperate thread on the topic.

even with all those posts I still don't understand the differences

 

[jasaero]

I know this was asked many pages ago (hey, I'm still catching up!), but I never saw much of an answer. In DC, we have great LTE coverage and in fact I usually get 2-3 bars of 4G (on my Bionic) in the basement of our restaurant So, I'd saw it is a bit better/stronger than WiMax.
Obviously, your mileage will vary.

I was hoping this was ture as I didn't know anyone that had LTE yet here so thanks!

I posted some replies to this. It's more a product of frequency bands used than LTE vs CDMA vs WiMax for building penetration. VZW's LTE is 700mhz former analog TV spectrum and that low frequency big wavelength penetrates buildings WAY better than 1900mhz PCS that a lot of CDMA or GSM is on or the 2ghz+ that I believe most Clearwire WiMax is on and maybe a TINY bit better than 850mhz that will only be used by the carrier that has rights to the analogue spectrum to use in your area.

The difference is that for those of us who have surgically had our vanilla stock eyeballs replaced with microscopes or zoom lenses, or those who hold their phone about 2" from their face while reading, will notice a different sort of layout of pixels.

For the rest of us, it pretty much just means an extra 100 or so posts to look over. That's my take.

Sorta. I tend to think the real issue has to do with widely varying eyesight anomalies. Not just visual acuity either, but how we all process different colors and the effective refresh rate of our eyes and how this works with how they are processing the Pentile and whether their tricks end up working well for our individual visual system or not. Our eyes just work A LOT different than any visual display or capture systems and on top of that seemingly have different capability from many different aspects of how they actually show an image to us. PenTile if I am not mistaken tries to trick some of how our eyes work a bit more than a standard stripe pattern and it's more successful at pulling this off for some than it is for others, but most agree at high enough resolution it will go beyond most peeps ability to notice the trickery as it will get beyond their acuity to pick up on it.

 

[burntorangefan]

Best Android phone out right now. It will be relegated to one of the best in 2012.

As MC Hammer once said "can't touch this"

Agree, I'm really excited for this phone...The SD card "issue" is a non-starter for me, the differences in Pentile vs Amoled + are a non-starter. Looking at the WHOLE package, it will be the best Android phone for some time. Just really happy and eagerly awaiting Tuesday...I don't expect perfection, just a really great experience.

 

[mongstradamus]

Holy cow i had to scroll through endless posts and pages on rgbg and pentile. Somebody needs to put up some gifs of not 1 dead horse being beaten but hundreds lol

My god that was more painful than the camera megapixel posts because it went on so darn long.

Start up a seperate thread on the topic.

The Samsung Fascinate doesn't have bad call quality per se, it is more of a radio reception issue than anything else. I can be sitting in my house with my phone, my girlfriend's phone and our home phone (we use a cell as a home phone since it is cheaper and affords us an extra upgrade ) and my Fascinate will always have the worst reception of the bunch. There is usually a 10 to 15 dbm difference between my phone and others around me.

I have an similar phone with the captivate it seems like when you touch the phone you lose an bar or two. Kind of similar to the iphone 4 death grip

 

[BlueBiker]

It's not really semantics. An 800x480 PenTile display displays an 800x480 image.

Everyone keep in mind that engineering, like life, is all about compromises. This isn't Samsung's choice to put in a Pentile display. It's just reality.

Let the record show that I'm exerting extreme willpower and declining to add a detailed and potentially witty reply to these PenTile posts here. Ohhhh the painnnn, the painnn.

Guys! Guys! Please read this post before Steven deletes it, please know that I was number 1 and I made an appeal for human compassion to Steven so that I can keep my posts, which are almost at a thousand (oh my goodness!) and I really really think that maybe Steven is thinking about deleting hundreds of my posts

Oh Han, you coulda been a contender.

i was really impressed by the LG Optimus 3D though it only has an OMAP 4430, so i guess the OMAP 4460 will be pretty good, too... (still i don't know if the NP is a device I can keep for 2 years...)

Impossible. We all know that 4430 is ridiculously obsolete and that Nexus with a 50% faster CPU won't be fast enough for anybody.

Heaven forbid anyone learn anything.

I'm making all the answers A or D, and throw some true/false in there too.

I'm gonna have two versions on my Test: R/G/B/G and R/G/B/W.

Because when a device touts a 4.5, 4.7...5" screen. I want to be able to use what they are offering. I see no point in having software keys on a bigger screen if I can't use the entire screen, always. Seriously, whats the point of advertising a 4.65" screen if you can only use it for one or two things?

There's no point to this argument. If you're upset that a screen advertised as 4.65" loses a small amount of space to buttons, then just mentally subtract .4" from the spec and then either buy or don't buy the phone.

Reminds me of the old days when CRT monitors were over-advertised, so that a 22" CRT really only had about 20.5" of viewable area due to the bezel. We survived the era, we just accommodated the marketing-friendly specs we were given!

 

[BlueBiker]

Hmmmm, I get more Thanks for not posting PenTile junk than I do for posting it. Must be a message in there somewhere.

Wonder if there's a way to monetize not posting PenTile / CPU / megapixel stuff in here. Say, $.10 per viewer per day of uncluttered thread?

 

[BlueBiker]

Okayyyy I have it figured out now: If you either talk about PenTile or you talk about not talking about PenTile, it gets moved here. Guess I can work w/that.

 

[r4yN]

Correct. Consider this GSMArena comparison image between the Galaxy Note, GS2 and iPhone 4.

The Note's screen is an order sharper than the SGS2 (consider that this is a hardcore macro shot, and the 'flyscreen' is invisible with the human eye - consider the visible grid in the iPhone 4 display) and actually appears to have better color reproduction.

Then consider, the Nexus Prime has a ~10% denser screen than the Note.

the white is much better on the NOTE [compared to the SGS2]... hopefully we get this (non-bluish) white on the NP, too...

i was really impressed by the LG Optimus 3D though it only has an OMAP 4430, so i guess the OMAP 4460 will be pretty good, too... (still i don't know if the NP is a device I can keep for 2 years...)

Impossible. We all know that 4430 is ridiculously obsolete and that Nexus with a 50% faster CPU won't be fast enough for anybody.

excuse me for being worried that the NP won't be able to play 3D-games that release in the next 2 years... there will be quadcore early next year, so if the game developers script their games for quadcore, we would have problems with a dual-core device...

 

[Teegunn]

the white is much better on the NOTE [compared to the SGS2]... hopefully we get this (non-bluish) white on the NP, too...

I love the high contrast colors of samoled, but the greyish whites really kill it for me. the whites on my DX2 (yes, pentile) are the brightest of any phone I have seen. Let me mention that my DX2 seems to have a brighter screen than other pentile screens I have compared it to (yes with same screen brightness settings of course) side by side. This would include many different DX2's and bionics. In other words, I wonder if there weren't different runs of pentile screens and some are natively brighter than others. I am digressing a bit, but my point is that having true, bright whites is VERY important to me in a display. let me also comment that the colors and saturtion of my DX2 screen is quite nice too. Not at all washed out. Yes, VERY close up, you can see the petile effect, but for normal viewing it's a non issue and the fantastic brightness more than makes up for any penitile negtives. Where this is leading is that if the new samoled tech can include much better white levels, I am probably going to be very happy.

 

[BlueBiker]

excuse me for being worried that the NP won't be able to play 3D-games that release in the next 2 years... there will be quadcore early next year, so if the game developers script their games for quadcore, we would have problems with a dual-core device...

I don't think there are many (any?) PC games that depend on quad-core, and those have been out since January of '07. Usually games are written to run well on whatever hardware is most commonly owned.

But you're right that technology marches on, and what seems fast today won't be as impressive in 2yrs. If that's important to you, I can see why you'd want to wait for something w/more leading edge 3D performance.

 

[EarlyMon]

Okayyyy I have it figured out now: If you either talk about PenTile or you talk about not talking about PenTile, it gets moved here. Guess I can work w/that.

Hey - it's Saturday. Figuring out what to move and what not to move wasn't easy.

PenTile has fewer subpixels, but they're larger. An HD RGB screen will light up 921600 small red subpixels, while PenTile will light up 460800 big red ones. I have no idea how power comparisons come out here.

Now that we have our own thread, I can happily square that point away.

Instead of small vs. big, the math is simple - PenTile subpixels are 50% larger than rbg subpixels.

1 pixel = 3rgb = 2 pentile, so pentile = 1.5 rgb - all other math flows from there, but there's the degenerate case to clarify:

On a hypothetical 3"x4" screen, using the same chemical formulations for SAMOLED/+ pixels, displaying an all-red field, the rgb screen will light up:

1/3 x 3 x 4 = 4 square inches of the screen

Whereas the Pentile will light up:

1/4 x 3 x 4 = 3 square inches of the screen

To produce the same effect, the PenTile will have dynamically increase brightness (and consume more power) - and by design, it does.

Spoiler

Assume that an rgb subpixel represents a unit area.

Red would be produced by 921600 unit areas for rbg.

Red would be produced by 460800 x 1.5 = 691200 unit areas for pentile.

691200/921600 = 3/4, same ratio for the shortcut math I started with, comparing ratios of 1/3 and 1/4.

There is an error term due to mask width, but it's minor.

And if you look at fields of color and work down, you'll find it always comes out this way, regardless of pixel sizes.

If my hypothetical 3x4 pentile screen had only two rgbw pixels, a full field display of red would still be 3 square inches.

Hope that clarifies why PenTile needs that processing, has that processing, and while honestly claiming many benefits - does not save power or use more, integrating over a full range of use cases.

It just is what it is.

 

[BlueBiker]

I love the high contrast colors of samoled, but the greyish whites really kill it for me.

Agreed, the whites in the SGS2 pic above look awful. I don't remember noticing poor whites on the Droid Charge (w/same screen) I had for a few weeks. I don't know what to think, but I sure hope Nexus is bright w/better color fidelity.

 

[EarlyMon]

I don't think there are many (any?) PC games that depend on quad-core, and those have been out since January of '07. Usually games are written to run well on whatever hardware is most commonly owned.

But you're right that technology marches on, and what seems fast today won't be as impressive in 2yrs. If that's important to you, I can see why you'd want to wait for something w/more leading edge 3D performance.

Hey, are we gonna get kicked out of the PenTile thread for talking GPUs?

In other forums, I was able to segregate various tech threads that made everyone happy.

I have no intention of kicking anyone out anywhere.

If we need to discuss processor handling of the display, this is a good place.

If we need to discuss other processor specifics, let's get together and decide what threads we want.

While others are posting happy lucky funny looky images in a thread that will get locked, we'll build sustaining tech threads that will be of benefit to all Nexus newcomers throughout the product lifetime, concentrating on areas of specific interest to make wading through the tech details easier for all.

Hope that works - ok to discuss here if not.

 

[EarlyMon]

IMO, Pentile tech positives (power consumption, sharpness, outdoors clarity) outweigh the negatives (grain effect in some background and some color trailing), but just BARELY). The grain is not an issue to me on a small display, but the object trailing can be annoying, since some games (especially emulators) give off trail effects for some moving objects (especially red).

If newer pentile displays have no trail effect, I would be happy. That all said, an IPS panel like on the iPod 4 is still the best display tech and there should be more devices with the tech this time next year, or earlier (Hitachi is ramping up capacity of their own version).

Screen ghosting - aka lag - aka persistence problems.

I hear you, I hate it. The Sharp mobile super ASV tech doesn't suffer it either (I have that on my phone, it's coming to many others).

Just a sorta tangential link for those unfamiliar -

TFT LCD - Wikipedia, the free encyclopedia

It's not Nexus or SAMOLED info in that link (and it's a bit out of date, but close enough for rock and roll), but others finding this thread may want to know what IPS means - again, not magic, just a tech description.