View Full Version : Why pentile? - N9 AMOLED screen comparison (i8910, GS, GS2, N900, droid, E7). Color performance pentile vs rgb
After all the talk about pentile, plus etc. I decided I have to make some conclusions for myself.
<UPDATE> I was trying to figure out why do manufacturers choose pentile screens. I think I have nailed the truth.
http://outofbounds.gr/blog/wp-content/uploads//2011/10/subpixel-size.png
As you see, the latest Samsung phones have slightly smaller subpixels but still the subpixel size is the limiting factor. So where manufacturers need to pack more pixels in the same real estate, they choose pentile, which in reality is a trick for higher perceived resolution with the exact same number of subpixels.
The subpixel diagonal is not real, it is just assuming that the subpixels are square, but I calclulated so that we have a human-readable measure of comparison.
</UPDATE>
After some research I found the following interesting results
1. Samsung provides 98% of the world's amoled screens (so it can be safely inferred that Nokia screens are indeed samsung)
2. Before the Super Amoled HD (Galaxy S2 HD, Galaxy Note - both pretty new devices I was wrong, both pentile, so the limit still exists) it seems there was a limit at the dpi of RGB stripe AMOLED screens around 220 ppi (Samsung, being the manufacturer of the screens probably has earlier access to new AMOLED technology, so very possibly Nokia had no choice but to equip the N9 with a pentile AMOLED to be able to keep the ppi count)
Following there are some closeup pictures of some screens (LCD and AMOLED). It is interesting that the N900 screen is made from the start to be landscape (it has the pixels rotated 90°) By the way the orientation of the photos does not correspond to the real orientation.
N9
http://www.outofbounds.gr/blog/wp-content/uploads/2011/10/N9.jpg
i8910
http://www.outofbounds.gr/blog/wp-content/uploads/2011/10/i8910.jpg
Galaxy S
http://outofbounds.gr/blog/wp-content/uploads//2011/10/galaxy-s.jpg
Galaxy S2 (not taken by me)
http://outofbounds.gr/blog/wp-content/uploads//2011/10/galaxy-s2.jpg
N900
http://outofbounds.gr/blog/wp-content/uploads//2011/10/N900.jpg
LG Optimus 7
http://outofbounds.gr/blog/wp-content/uploads//2011/10/optimus-7.jpg
Motorola Milestone
http://outofbounds.gr/blog/wp-content/uploads//2011/10/milestone.jpg
You need a legend on there, perhaps something to show you the size of 1 mm.
If you can find the orientation, that would also help visualize the differences. All-in-all, nice job
the photos were mostly targeted to prove that rgb stripe isn't the new improved standard, as many like to say, just the old tech used in the N85, i8910 etc and got replaced with pentile later for what it seems to be pixel density constraints. Another thing I suppose we can see is the distance between subpixels, but this is a little bit fuzzy, because of the glow that maybe makes bright spots bigger on a photo, and the same brightness is very difficult to achieve on all phones.
I can try and do a more 'scientific' test, but this one just shows the subpixel layout. Scale, brightness, orientation etc are random.
The Galaxy Note screen is pentile. That fits to my theory that the dpi of rgb amoleds has am upper limit at about 210ppi, and that indeed the N9 has one of the best possible configurations for it's screen size.
Update: The E7 screen is RGB Stripe http://www.outofbounds.gr/blog/wp-content/uploads/2011/10/closeupE7.jpg and the Galaxy Nexus is Pentile. Another nice observation is that the color performance of RGB stripe seems to be much superior to pentile.
The pentile as you can see in the picture fails to hide the fact that it has 33% more green subpixels
http://outofbounds.gr/blog/wp-content/uploads//2011/10/N9vsE7.jpg
I was trying to figure out why do manufacturers choose pentile screens. I think I have nailed the truth.
http://outofbounds.gr/blog/wp-content/uploads//2011/10/subpixel-size.png
As you see, the latest Samsung phones have slightly smaller subpixels but still the subpixel size is the limiting factor. So where manufacturers need to pack more pixels in the same real estate, they choose pentile, which in reality is a trick for higher perceived resolution with the exact same number of subpixels.
The subpixel diagonal is not real, it is just assuming that the subpixels are square, but I calclulated so that we have a human-readable measure of comparison.
updated in the first post too for posterity
It does not matter is it pentile or how many super or plus words is used, N9 screen is really good one, specially because of its high brightness (to make it useable even outside - a clearly better one in a bright light compared to GS2 or iPhone 4/4S) ... http://www.gsmarena.com/nokia_n9-review-659p2.php (comparison on the down of that page, some shows brightness of each model) ... well, there should be also some improvement applied for sharpen fonts in PR 1.2 of N9, some is really welcome for N9 ...
kiddn97583
2012-01-11, 11:37
Sorry to say this....
but I'll take IPS or SLCD over amoleds family any day any time :(
Amoled screens have so many problems as discussed here in other thread.
However as you mentioned, for the usage of outdoors I tend to agree with you, clear black display by Nokia really helped it out (but not Amoled I think.
IMO, to have more usage outdoors is by simply cutting down the glare of sunlight, to do that I ask an expertise at local to apply an Anti-reflective coating film on screen
(I know it may be an over-do as N9 already has CBD)
My point is when choosing IPS/SLCD but still worrying about glare, we can simply apply that high-grade coating film on screen to get the best of both worlds :D
It does not matter is it pentile or how many super or plus words is used, N9 screen is really good one, specially because of its high brightness (to make it useable even outside - a clearly better one in a bright light compared to GS2 or iPhone 4/4S) ... http://www.gsmarena.com/nokia_n9-review-659p2.php (comparison on the down of that page, some shows brightness of each model) ... well, there should be also some improvement applied for sharpen fonts in PR 1.2 of N9, some is really welcome for N9 ...
javispedro
2012-01-11, 12:27
Pentile uses less battery too.
Keeping screen size and resolution (variables) out of the equation, I'd prefer Samsung's SAMOLED+ over everything.
It uses about 50% less battery than IPS screen at the same brightness, and both are equally viewable under sunlight except the (S+) having deeper blacks and better saturation.
SLCD with TFT-back is king of brightness and sunlight performance, but they suffer from shorter viewing angles than IPS or AMOLED types, and bad black levels which also gives them bad colour reproductivity.
Now it is very difficult, even with my Pilot eyes, but I can actually spot the "pixel jag" on the Galaxy Note...which is caused by the Pentile layout. Like said before, they just knock off one subpixel and share a neighbouring one, which saves battery but causes these "unsightly" jagging. Now I'm not sure what I would rather prefer, the Note's display or a qHD SAMOLED+ display?
Keeping screen size and resolution (variables) out of the equation, I'd prefer Samsung's SAMOLED+ over everything.
It uses about 50% less battery than IPS screen at the same brightness, and both are equally viewable under sunlight except the (S+) having deeper blacks and better saturation.
SLCD with TFT-back is king of brightness and sunlight performance, but they suffer from shorter viewing angles than IPS or AMOLED types, and bad black levels which also gives them bad colour reproductivity.
Now it is very difficult, even with my Pilot eyes, but I can actually spot the "pixel jag" on the Galaxy Note...which is caused by the Pentile layout. Like said before, they just knock off one subpixel and share a neighbouring one, which saves battery but causes these "unsightly" jagging. Now I'm not sure what I would rather prefer, the Note's display or a qHD SAMOLED+ display?
kiddn97583
2012-01-11, 14:19
I wonder, maybe the screen battery consumption can be a fake issue, since GS2, note, iphone4 all drain battery pretty quick, don't they? Meaning screen won't be a sole factor.
I prefer cool color temperature, so AMOLEDs won't be my option.
Battery wise, they all drain pretty fast :(
========================================
Edit:
WOW!!!!!! It's official Lumia 900 will sport "RGB" Clear Black Display.....Why not on my N9 :mad::mad::mad:
If no IPS/SLCD, I can still take RGB AMOLED :P
Pentile uses less battery too.
pentile RGBW in LCD screen uses less battery power than it's RGB counterpart but according to oled-info.com pentile RGB AMOLED (N9) uses 18% more power than RGB Stripe
@kiddn the answer is in the first post. Couldn't be done.
javispedro
2012-01-17, 18:38
according to oled-info.com pentile RGB AMOLED (N9) uses 18% more power than RGB Stripe
That assertion defies common sense, so it would need some backing. Both pentile layouts have a severely reduced number of pixels vs the traditional arrangement. And less OLED pixels surely means less power usage.
Also, I bet that the reason they chose green is because the human eye has better response to green.
Also, I bet that the reason they chose green is because the human eye has better response to green.
It is. Green controls the luminance.
Sorry, I don't care about technology, the screen of the N9 is obviously one of the best actually.
evujumenuk
2012-12-16, 23:04
Let's see. One could model an RGBG display as an RGB display where a pair of pixels is missing one R and B pixel each. To compensate for this, the singular R and B pixels would need to be driven in a way as to double their maximum output. Alternatively, the G subpixels could be halved in surface area and, thus, luminosity.
Since chromatic acuity in one's eye is worse than luminous acuity, one would not lose image quality.
So, given a specific subpixel budget, a PenTile display would be better if the pixel density is high enough to test the limits of the human eye.
Did I miss anything yet?
That is the point, and that is why it is being used. For a given number of subpixels (max that fit in a specific screen) pentile is better. Of course if tomorrow someone manages to fit 50% more subpixels in the same space and decides to go rgb the result will be better. But with 50% more subpixels it would be better to go pentile again with 50% higher resolution. Chicken and egg :)
(for a direct comparison compare an E7 with an OG Galaxy S)
WVGA pentile is better than nHD rgb.
Pentile is a cooler technology, more hitech.
Its probally because this was a one off device and nokia wanted to keep it as cheap as possible, cheap proc, pentile, cheap speakers, etc... I love my n9, but you can tell other than form factor, not as much love went into the hardware as a n8 or 808
Its probally because this was a one off device and nokia wanted to keep it as cheap as possible, cheap proc, pentile, cheap speakers, etc... I love my n9, but you can tell other than form factor, not as much love went into the hardware as a n8 or 808
Probably not because the Lumia 800 uses the same pentile screen. I don't know about the other Lumias, though.
evujumenuk
2012-12-18, 08:39
I found a paper which kind of explains the physiology behind PenTile:
http://www.cvs.rochester.edu/williamslab/drw_pubs/Roorda99nature.pdf
The original PenTile layout had five subpixels in a group (thus the name - penta-tile), and the results show why: the occurrence of "blue" cones is so much lower that using less of them makes sense. The low rate is also consistent.
For red and green receptors, their ratio seems highly variant so making a case for skimping on red subpixels seems more difficult.
Green has one advantage, it generates responses in all three types of receptors, so for pure brightness information, resolution would be the greatest here. This looks like a possibility to trade off color reproduction accuracy for brightness and perceived "crispness" (as opposed to actual high resolution), and this is what's probably done in AMOLED PenTile displays.
Oh yeah, there's one problem with the study: The sample size is pretty much completely ridiculous (two). This paper is from 1999, so maybe there just isn't any more recent, comprehensive research. I guess PenTile was driven foremost by cost considerations and previous experience from video compression.
I admit that I lack real insight on how perception of contrasts and colors interrelate so maybe there is an opportunity for enhanced subpixel layouts that I can't see. Right now I think whether PenTile is better or worse doesn't have many hard and fast arguments either way...
ste-phan
2012-12-18, 08:52
Probably not because the Lumia 800 uses the same pentile screen. I don't know about the other Lumias, though.
The Lumia 800 was a quick and dirty job to get a mainstream WP 7 phone on the market FAST.
My eyes don't care about the tech behind Pentile. It just looks rubbish and the colour inconsistencies and dancing and glowing text characters were the primary reason for me to ditch the N9 in disgust a couple of weeks after I got it. Yes I have checked other N9's.. Same or worse problems.
Nokia is infamous for insulting customers with bad screen tech. Try to find an N8 with a good (non purple tinted screen)
They just count on the majority of their users to not notice or be undemanding.
I think I have said this previously, the quality of the screen depends a lot on psycological/physiological differences between people.
I have a co-worker who cannot use amoled screens, whether pentile or RGB. He said of my previous E7 thet it strained his eyes and N9 is even worse, he claims that the colours flicker so bad it causes physical dicomfort.
For myself, I have no such problems, I find N9 screen easy to use and having nice, even colours.
I think there is similar thing with video projectors using DLP technology, some people claim that they see distracting rainbow effect on the device and others do not see that.
ste-phan
2012-12-18, 09:28
I have a co-worker who cannot use amoled screens, whether pentile or RGB. He said of my previous E7 thet it strained his eyes and N9 is even worse, he claims that the colours flicker so bad it causes physical dicomfort.
This. Although I haven't tested the E7, I generally couldn't agree more with your colleague.
I suggest R&D teams concerned with screen technology should focus more on humans and ergonomics rather than strictly on paper specs.
I think we can be 100% positive that the complaints about the Japan made N900 LCD display will be similar for most and rather containable.
-small characters when not zoomed due to high res screen with small screen diameter
-low colour rendition in sunlight
-blacks not beautiful
But non of those disadvantages of the N900 LCD are as aggressive in nature as the tyresome side effects experienced by some with Pentile.
Needless to say, I am going to keep my career as lab rat for Samsung AMOLED research as short as possible even though my friends phone will show a brighter screen in the desert.
But the whole point is, how many people find the displays pleasant to look at, and how mny distracting??
I am ready to bet on the ratio being lower than 1/20 on favour of people who see nothing wrong with AMOLED screens, there are just random few who feel that they are not good looking. (they are just so very loud in their opinions that it makes the issue look important...)
ste-phan
2012-12-18, 10:23
But the whole point is, how many people find the displays pleasant to look at, and how mny distracting??
I am ready to bet on the ratio being lower than 1/20 on favour of people who see nothing wrong with AMOLED screens, there are just random few who feel that they are not good looking. (they are just so very loud in their opinions that it makes the issue look important...)
No it is the AMOLED that screams in loud capitals that it is the best solution because it has the brightest colours.
The 19/20 that accept this as truth are also the ones that settle with non-calibrated 200 USD monitors and turn their TV sets and camera's to high contrast high saturation.
The problem here is that bright colours win over image quality.
Good looking and continuously and comfortably usable for hours and hours are not the same.
evujumenuk
2012-12-18, 10:33
For me, the absolute blacks are the defining feature of OLED. Of course, my N9 could use color calibration.
Nokia is infamous for insulting customers with bad screen tech. Try to find an N8 with a good (non purple tinted screen)
They just count on the majority of their users to not notice or be undemanding.
Man, how could anyone NOT notice the edge color striping when, say, looking at the task switcher with an app open?
Or the low-power mode clock?
Or anything white against a black area with the LCD in low-power mode?
The entire screen is tinted freaking green, setting color temperature to "Standard" accentuates this ("Vivid" hurts my eyes, so I avoid it)
While perfect blacks look really good on the display, the garbage color reproduction for UI elements (where you have large blocks of single colors, often contrasting) was a major turn-off when I first got my N9.
Man, that was nothing but a shaft for N9 users - Pentile screen, without the high PPI. It would've been much appreciated if they stuck a 1280x720 Pentile, or a non-Pentile 848x480 LED screen.
Some sorry souls also see pink/green flickering on plasma screens :D LOL I'm glad I'm not one of them :p
Pentile is cool. It's much better than people give it credit for. The 3.9 inch screen on the N9 is actually has almost as high PPI as the SGSIII screen.
Another thing. A 480 x 800 RGB has 480 x 800 addressable pixels (each full RGB pixel). A 480 x 800 pentile has 960 x 800 addressable pixels (each sub pixel). Even though a pentile screen has lower sub pixel count and thus lower "real" PPI, this is offset to a large degree by adaptive sub pixel rendering.
As screen technology becomes cheaper and PPI count higher, everything will be pentile (or similar) in the end due to reduced production cost.
javispedro
2012-12-18, 18:57
Another thing. A 480 x 800 RGB has 480 x 800 addressable pixels (each full RGB pixel). A 480 x 800 pentile has 960 x 800 addressable pixels (each sub pixel). Even though a pentile screen has lower sub pixel count and thus lower "real" PPI, this is offset to a large degree by adaptive sub pixel rendering..
Actually... A 480x800 RGB has 480x800x3 addressable subpixels. A 480x800 pentile has too 480x800x3 adressable subpixels, but the controller mangles those into 480x800x2 subpixels.
Aka Pentile RGBG actually has 2/3 the amount of subpixels, no matter how you look at it.
Subpixel rendering is not only also present in the RGB layout, but is also _easier_ to do.
And just google around for 'pentile yellow pink' or 'pentile checkerboard' to see how many people detect PenTile's artifacts. Specially at a (by today's standards) very low resolution handheld such as the N9.
Actually... A 480x800 RGB has 480x800x3 addressable subpixels. A 480x800 pentile has too 480x800x3 adressable subpixels, but the controller mangles those into 480x800x2 subpixels.
Aka Pentile RGBG actually has 2/3 the amount of subpixels, no matter how you look at it.
Subpixel rendering is not only also present in the RGB layout, but is also _easier_ to do.
And just google around for 'pentile yellow pink' or 'pentile checkerboard' to see how many people detect PenTile's artifacts. Specially at a (by today's standards) very low resolution handheld such as the N9.
Not on Samsung screens. But please feel free to correct me if I'm wrong.
javispedro
2012-12-18, 19:05
Probably not because the Lumia 800 uses the same pentile screen. I don't know about the other Lumias, though.
They got rid of Pentile in the next Lumia and never used it again. That should say something...
Not on Samsung screens. But please feel free to correct me if I'm wrong.
PenTile IS Samsung.
They got rid of Pentile in the next Lumia and never used it again. That should say something...
PenTile IS Samsung.
I thought it was Clairvoyante ??
Anyway, the only RGB screen that is addressable at each sub pixel is the S Stripe,and that is not even a "proper" RGB. So I have heard.
javispedro
2012-12-18, 19:58
Anyway, the only RGB screen that is addressable at each sub pixel is the S Stripe,and that is not even a "proper" RGB. So I have heard.
This is going offtopic, but by definition each and every RGB screen is fully subpixel 'addressable'. This is because RGB itself is used for color representation! If you increase or decrease the amount of "red" in the red channel, you are effectively controlling the red subpixel.
They got rid of Pentile in the next Lumia and never used it again. That should say something...
It just says that the max resolution of WP7 was so low that it was possible to cram 3 subpixels/px. Or if you see it the other way around, with such a low ppi the only thing they could do to mitigate the loss of quality was to go RGB. Now for the 920 they went LCD which is an entirely different ballpark.
Btw clairvoyant is a samsung subsidiary if i'm not mistaken.
It's simple. You can't go well over 200ppi with RGB amoled.
It's simple. You can't go well over 200ppi with RGB amoled.
So the initial question should be, why do manufacturers still use LCD?
szymeczek34
2012-12-19, 13:57
I guess it's cheaper to make. And there's less faulty screens made in production. I don't expect HTC or Apple or Motorola to use amoled. They won't change something that in the end doesn't matter for consumer, because 90% of them don't know the difference and don't care. Stupid person is a happy person. Just if you would show old Nissan Almera to North Korean people. For them it would probably be a car out of this time, modern, safe, fast, economical but we, who know more and have comparison will say that it's old and slow.
javispedro
2012-12-19, 14:13
It just says that the max resolution of WP7 was so low that it was possible to cram 3 subpixels/px. Or if you see it the other way around, with such a low ppi the only thing they could do to mitigate the loss of quality was to go RGB. Now for the 920 they went LCD which is an entirely different ballpark.
Btw clairvoyant is a samsung subsidiary if i'm not mistaken.
It's simple. You can't go well over 200ppi with RGB amoled.
Samsung's own Galaxy Note 2 is RGB AMOLED and is 260ppi. So you quite can go over 200ppi.
Of course, the real reason Samsung (ab)uses Pentile is that they like to boast their über resolutions over Apple ones, when actually the Galaxy S3 is ~200ppi (because of Pentile). Aka much less that the iPhone and even less than the retina iPad.
Samsung will argue that 200ppi Pentile actually looks like 300ppi because of human eye aspects, etc.
In my opinion, a true RGB layout at 200ppi looks much better than Pentile at 200ppi, because of all the Pentile artifacts. Compare the N9 vs the N950. Thus, saying that 200ppi Pentile looks like 300ppi Pentile is hilarious at best.
Samsung KNOWS that they will not sell as many devices if they concede that Apple has nearly 1/3 more pixels, despite the screen being smaller, so they start talking about Pentile.
So the initial question should be, why do manufacturers still use LCD?
LCDs, specially IGZO and the like, can be made with very, very high ppis. They also have a longer lifespan. In my opinion, both things beat AMOLED's color reproduction.
thedead1440
2012-12-19, 14:17
I guess it's cheaper to make. And there's less faulty screens made in production. I don't expect HTC or Apple or Motorola to use amoled. They won't change something that in the end doesn't matter for consumer, because 90% of them don't know the difference and don't care. Stupid person is a happy person. Just if you would show old Nissan Almera to North Korean people. For them it would probably be a car out of this time, modern, safe, fast, economical but we, who know more and have comparison will say that it's old and slow.
Motorola's Razr models I'm sure a number of them are using AMOLED from Samsung...
szymeczek34
2012-12-19, 14:25
My bad, you're right. I don't know how I could forget about RAZR line. But they're from samsung. Same goes with Nokia's screens, Samsung produces them. I'm just curious from whom HTC buys screens.
thedead1440
2012-12-19, 14:27
My bad, you're right. I don't know how I could forget about RAZR line. But they're from samsung. Same goes with Nokia's screens, Samsung produces them. I'm just curious from whom HTC buys screens.
LG or Sharp?
Samsung's own Galaxy Note 2 is RGB AMOLED and is 260ppi. So you quite can go over 200ppi.
True. So that limit doesn't exist anymore. I stand corrected. However this wasn't true when the N9 was out.
On the other hand, comparing the E7 with the N9 I'd always take the N9 despite the artifacts and not-so-good color. 180, (even if they are more 'real') ppi is too low.
With subpixels able to shrink more, we could have 800x480 rgb AMOLED on the N9 today, or qHD pentile. What would be best then given that 260ppi is not too low? How far can you go up the ppi count until you can't tell the difference? At extreme ppi's which one looks better? X ppi RGB or X*1.33 ppi pentile.
My 3 year old (in a few weeks) Samsung Wave has a 3.3 inch 480x800 pentile amoled display. That is a PPI of 283 or a "true" PPI of 214 (due to pentile).
Surely the technology hasn't been on hold the three last years.
IMO Amoled is better, pentile or not. Black is black is more important than seeing grains with a microscope.
True. So that limit doesn't exist anymore. I stand corrected. However this wasn't true when the N9 was out.
On the other hand, comparing the E7 with the N9 I'd always take the N9 despite the artifacts and not-so-good color. 180, (even if they are more 'real') ppi is too low.
With subpixels able to shrink more, we could have 800x480 rgb AMOLED on the N9 today, or qHD pentile. What would be best then given that 260ppi is not too low? How far can you go up the ppi count until you can't tell the difference? At extreme ppi's which one looks better? X ppi RGB or X*1.33 ppi pentile.
Not true. It has s-stripe RGB. It has the same "low" horizontal resolution as any pentile screen (2 sub pixel per pixel). It does has better vertical resolution, at sub pixel level, than any other screen.
http://andu.nm3.kr/files/attach/images//607/055/15b0dbe723d0082743d6704fead13075.png
evujumenuk
2012-12-19, 16:25
S-Stripe looks equivalent to RGB, the red and green subpixels are just rotated.
I think it's even better because less space is wasted on borders between pixels.
It also looks like subpixel hinting would work better with subpixels that aren't three times as high as they are wide.
javispedro
2012-12-19, 16:30
At extreme ppi's which one looks better? X ppi RGB or X*1.33 ppi pentile.
THAT is the PenTile question. While I cannot give a meaningful answer for X > 200ppi, my opinion is quite strong on 200ppi screens (~N9), where it basically sucks.
Note that the traditional RGB layout also has some artifacts. But simply put, RGB screens are everywhere -- so I am already totally used to them.
My 3 year old (in a few weeks) Samsung Wave has a 3.3 inch 480x800 pentile amoled display. That is a PPI of 283 or a "true" PPI of 214 (due to pentile).
A ten year old Sony VAIO has a true PPI of 260. The Nokia Internet Tables have had similarly high PPIs for ages. Screen technology has not advanced much in the past decades.
Not true. It has s-stripe RGB
What is exactly false? The layout is RGB, and it uses 3 subpixels per pixel. There are several arrangements in use for RGB pixels (e.g. wedges, etc.)
What is exactly false? The layout is RGB, and it uses 3 subpixels per pixel. There are several arrangements in use for RGB pixels (e.g. wedges, etc.)
Good question. The sub pixel resolution is less than striped RGB. Striped RGB will therefore potentially achieve greater sharpness for the same (full) pixel count, in horizontal direction. For instance you want to make a white dot at the intersection of all 4 pixels with a diameter of one (full) pixel. For the RGB you will have 6 pixels in horizontal direction you can use (+ more on each side if needed). For S-stripe you only have two. Hence, the accuracy you can achieve is less. In vertical direction it will be a bit more for S-stripe than RGB.
But, and this is the clue to pentile as well. At each sub pixel intersection you have all three colours available for S-stripe and pentile, but only two for RGB. RGB stripe only has high accuracy when going into the pixel, but low when going out. Pentile has high accuracy when going out, but lower (in saturated blue or red) when going into the pixel. S-stripe has high accuracy all over.
Clearly the s-stripe is superior to RGB stripe and pentile. I suspect we will see lots of S-stripe amoled in the future, also with relatively low pixel count.
ste-phan
2012-12-19, 18:13
Black is black is more important than seeing grains with a microscope.
Kindly don't compare normal eyesight with microscope vision.
In Asian metropoles, I see a ridiculous amount of teenagers wearing glasses.
Are they the perfect target customers for Pentile made in Korea? :rolleyes:
evujumenuk
2012-12-19, 19:02
I guess we can agree that S-Stripe should generally be a superior RGB. Personally, I can't think of a better layout that's not just a tweak of the four points that define the borders in the whole pixel, or simply a rotation.
Regarding PenTile, the original PenTile layout looks interesting:
http://upload.wikimedia.org/wikipedia/commons/7/77/Subpixel_rendering_RG-B-GR_alternated_geometry.png
Spatial resolution of the blue subpixels is exactly double that of that of the red and green subpixels. It's a conservative upgrade to RGB, but I guess subpixel budgets rule it out. However, rotating a subset of those pixels would make it possible to merge subpixels, this means trading pixels that fit neatly in a square grid for increased overall density.
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