Nokia Lumia 900 Review - Windows Phone with LTE
by Brian Klug on April 3, 2012 9:00 PM ESTDisplay Quality
Like the Lumia 800, the Lumia 900 uses an AMOLED display instead of an LCD. One of the chief differentiators between the two models however is the difference in subpixel rendering. Whereas the Lumia 800 used a 3.7“ PenTile RGBG SAMOLED panel, the Lumia 900 uses a 4.3” SAMOLED+ panel with an RGB subpixel stripe. Those names fit, that is, if we’re following Samsung’s naming scheme, and as an aside this is undoubtedly a Samsung panel.
The effective resolution of both displays are 800x480 WVGA, like all Windows Phones, however. Jumping up in display size pretty much necessitates that change to RGB, since PenTile really only works when subpixels are below human visual acuity. In addition, we’ve already seen 4.3" SAMOLED+ WVGA displays out of Samsung (see the Focus S).
I measured the Lumia 900 display using an i1D2 just like I’ve done with numerous other smartphones, though at this point the advanced color and gamut information will have to wait until I make some targets. Again, because AMOLED is emissive, black color pixels are literally off, so contrast graphs are omitted. The Lumia 900 doesn’t go super bright, like other AMOLEDs I’ve seen. In fact, it’s slightly dimmer than the Lumia 800’s maximum of 196 nits. Remember that going to a larger display, especially AMOLED due to its emissive nature, increases power demands as r^2 since we’re talking about areal size.
| Lumia 900 Display Metrics | |||
| Brightness Level | Black Brightness (nits) | White Brightness (nits) | White Point (K) |
| Low | 0 | 72.68 | 6635 |
| Medium | 0 | 140.06 | 6930 |
| High | 0 | 173.55 | 6812 |
Nokia was able to get the Lumia 900 display nice and close to 6500K, which is interesting considering how many other AMOLED displays I’ve seen which are up near 8000K or higher and noticeably blue all the time.
I glossed over ClearBlack on the previous Lumia reviews partly due to time constraints, partly due to not knowing the exact details of their optical path. That said, it was immediately obvious that the system used circular polarization’s behavior upon reflection to attenuate back reflections. However, since writing those reviews, Nokia has outlined their optical system in a conversations post, and the long and short of it is that the system consists of a linear polarizer and quarter-wave plate.
Incoming diffuse light gets vertically polarized by a surface polarizer, which becomes right hand circularly polarized when passing through the quarter wave plate. When circular polarized reflects off of a surface, it changes handedness - in this case from right to left handed circular. Upon passing through the quarter wave plate on its way out, this becomes horizontally polarized, which is then strongly attenuated by the surface polarizer with its fast axis aligned vertically on its way out, which acts like an analyzer. The end result is that outdoors the only reflection you’ll get is from the first surface, not the surface of the display itself, which does reduce resulting glare.
This change also permits the Lumia 900 to still look bright outside, and in turn allows Nokia to run the display at a lower brightness and save some amount of power. For a while I was waiting for some OEM to introduce a system using polarization to diminish back reflections, and Nokia has done it with ClearBlack.
Indoor viewing angles for the Lumia 900 are excellent as evidenced by the purple test pattern from WP Bench not changing color at extreme field angles. In addition, I subjectively can’t find any issues with the display - there are none of the other problems that affect the higher dot pitch AMOLEDs such as grain or mura. Outdoor viewing angles are likewise good for the Lumia 900 in part thanks to ClearBlack.
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tipoo - Wednesday, April 4, 2012 - link
It seems to me like Microsoft is deliberately capping WP7 phones so that Apollo phones will look even better by comparison, with the SoC single core limitations and screen resolution caps. I wonder if this phone or other WP7 phones will be able to get WP8 then, or if that will only be on dual core phones?melgross - Wednesday, April 4, 2012 - link
The OS can't handle multi cores or a higher Rez. That's just the way it is. Since that's going to limit sales, why would they deliberately want to do that?Yes, there's a fork of CE (which is what WP7 uses), which allows dual cores, but it has it's own problems as a phone OS.
tipoo - Wednesday, April 4, 2012 - link
But I'm still wondering if current phones will be able to get WP8. Since it has a new kernel, my guess would be no.N4g4rok - Wednesday, April 4, 2012 - link
It's possible, but my not be a profitable. There's always that ugly little trade off between going next generation or supporting legacy hardware.I think what they do with it will depend on how different the OS itself is in terms of features and UI. If it brings an entirely new suite of capabilities that would not be as efficient on single-core platforms, then it might not hurt to let the previous generation to go to pasture. Otherwise, they might loose that regard as an efficient handset.
Then again, who knows if the kernel in Apollo will be built with the intension to utilize dual core hardware, or if the upgraded hardware will be mainly for drawing attention from developers.
Braumin - Wednesday, April 4, 2012 - link
I don't think the kernel will matter. The new kernel will support far more hardware than the old one.When you upgrade your PC from Windows XP to Windows 7, the kernel changes, but the hardware doesn't.
I assume that since basically there are only a couple of different hardware specs for WP7, they will make it possible. The question of course is whether the hardware vendor will bother with the upgrade. In most cases, I would say no, but I also think Nokia will be the exception.
We'll see in the fall though!
ol1bit - Wednesday, April 4, 2012 - link
Yea, Microsoft is way behind in the phone game. They need to keep up, how long have they been play with WP7 now, and still no high rez or multi-core?I think MS continues to make bad decisions. Who wanted a single threaded OS 3 years ago? They just looked at Apple current and said we like that, and lets design ours just like that.
Goggle looks to the future and started Android out multi-threaded. I hope Alppol isn't a hack job with fake multi-threading added in.
robco - Wednesday, April 4, 2012 - link
The $99 price point is interesting, same as the iPhone 4, but with more storage and LTE. I suppose that works since they're still behind the 4S a bit.I like WP7 and if I decide to ditch iOS, it would be my next choice. I just hope MS will support more chipsets and higher display resolutions sooner rather than later. Of course the big issue for me, and others in this area, is the carrier issue in the US. I won't go back to AT&T. For many people the reception is fine and the service tolerable, but not where I live. So far the only WP7 handsets on Sprint or VZW are even more dated.
MS has a lot of ground to gain, but it's not as if they don't have the resources to throw at it...
NeoteriX - Wednesday, April 4, 2012 - link
Brian,Your insight into the display, and in particular, digging up the optical path of the ClearBlack technology, may be overlooked by many. But it's really something where your obvious optics education/background gives you and AnandTech significant added value over the droves of blathering nontechnical review sites and blogs.
Kudos.
EddyKilowatt - Wednesday, April 4, 2012 - link
If this is the kudos section, let me award one too, for posting and discussing the MediaInfo screencap showing the video and audio codec settings. That too is the kind of non-blathering, solid tech info that I'm glad you guys specialize in.(I actually googled "lumia 900 video bitrate"... and must confess I grinned a knowing grin when I saw AnandTech pop up in the first screen of hits.)
name99 - Wednesday, April 4, 2012 - link
"Interestingly enough Nokia does note the presence of Rx diversity for WCDMA on the Lumia 900 front and center, both under their “design” tab and under Data Network on the specifications page. It’s awesome to see another handset vendor realize that great cellular performance is noteworthy"I'm rather more cynical than you. Note that they do NOT support HSPA MIMO.
My guess is that at least part of talking up their diversity antenna is specifically to deflect from that --- throw out some techno-lingo about how we have multiple antennas to "maximize RF performance" and hope no-one notices some conspicuous holes in our HSPA features.