qwazix | # 1 | 2011-11-02, 16:32 | Report

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.



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


i8910


Galaxy S


Galaxy S2 (not taken by me)


N900


LG Optimus 7


Motorola Milestone

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Last edited by qwazix; 2012-07-05 at 21:51.

Kangal | # 2 | 2011-11-03, 03:48 | Report

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

qwazix | # 3 | 2011-11-03, 08:53 | Report

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.

qwazix | # 4 | 2011-11-18, 09:08 | Report

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.

qwazix | # 5 | 2011-12-30, 12:04 | Report

Update: The E7 screen is RGB Stripe 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

qwazix | # 6 | 2012-01-10, 12:53 | Report

I was trying to figure out why do manufacturers choose pentile screens. I think I have nailed the truth.



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

jaripi | # 7 | 2012-01-10, 20:45 | Report

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 | # 8 | 2012-01-11, 11:37 | Report

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

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Last edited by kiddn97583; 2012-01-11 at 14:44.

javispedro | # 9 | 2012-01-11, 12:27 | Report

Pentile uses less battery too.

Kangal | # 10 | 2012-01-11, 12:46 | Report

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?