On the n9 that i own, i didnt notice the black spots even in those conditions which you describe. the only thing that i do notice is the reddish/purple tint/bleeding on the left side of the screen ,as Benny has stated, is really visible and frustrating when using it in darker environments. it is barely visible in lighter conditions. Somehow, I think that this can be tweaked a bit on the software side with the color pallettes so that it isnt that noticeable, contrary to what the limitations of the amoled display. At this point anything that can be done to make it fix it just a bit would be great welcome to many n9 users, because this device is not cheap!

try messing with the ambient light sensor while in a light area so it thinks it's dark and visa versa. if there's no change to the bleeding/tint then it it's not related. i'd say the purple tint is due to the way the software is configured. it's probably down to more visibility the purple is used in daylight but needs to be toned down more for darkness.

I'm having the same problems with purple vertical lines during the landscape browsing of white webpages. I'm really annoyed with this and I'm already ready to get rid of this device. These kind of problems with a 700 euros device is unbearable...

Yesterday I checked the sample webpage posted in this forum earlier with my girlfriend's SGS II and there were no visible purple lines. Based on this one (unrepresentative) test I would assume that the problem is not solely because of Amoled technology. This suggests that the problem is caused by pentile matrix technology or software and only the last one of these can be fixed afterwards.

Now I'm really pissed about the fact that I gave Nokia a one more chance!

I just tried and simply creating the file /etc/X11/xorg.conf.d/screen.conf with the contents:
and rebooting makes the screen run at 24-bit color depth, however this also causes various problems. Things run noticeably slower, trying to switch to portrait seems to cause apps to freeze, the bar at the top doesn't display at all (although the menu when tapping it does appear), the vkbd randomly doesn't work and vsync seems to not quite work to mention a few I noticed with quick testing. No effect on the purple bleeding, but gradients do look much nicer.

Booting back to 16-bit depth, I just realized the device did not ask me for my lock code, when I booted at 24-bit depth...

I also noticed that those issues I think are color depth related don't show up everywhere. The example picture I posted earlier, for example, shows perfectly well in the image gallery. It just feels broken in the browser. (Plus, of course, application UIs, especially dark backgrounds, have this problem.) Strange.

Well... I tried to but... where the hell is this thing?

It seems to work, because when I switch off the lights, the screen becomes a little darker (and the lines even more visible). But I don't find any spot I could cover when the lights are on to make the N9 think it's alone in the dark with me.

It's possible the gallery does dithering when displaying images, but the browser quite obviously doesn't. The screen DPI is high enough, that it would probably be indistinguishable. I'd think graphics used in apps would be prepared dithered for the screen (although considering Nokia's specs claim 24-bit color, not all developers might be aware of needing to do this).

Just popping in to +1 on this thread.

I've got easily noticeable streaking in the browser (esp. its startup screen), where a vertical line of pixels (about 1/3 from the left) form the basis of the streaks (others have explained better!). So scrolling vertically whilst in portrait might not be so dodgy-looking as the streaks stay in the same place relative to the text, but scrolling vertically in landscape is like having a bad amiga demoscene effect going on in the background.

16bpp has always been the Maemo standard. AFAIK LCDs cannot display 24bpp anyway, but more like 18bpp. I don't know whether this is true for AMOLED, though.

On my N9 I can see very weak lines on bright white areas, but only if I look closely. Apart from that the display is fine.
Of course it has this green pentile tint when watching it from angles where on regular LCDs colors would totally get washed out.

IMHO if you're using the device normally, the display looks gorgeous. But if you look close, it becomes ugly.

I did some testing with the browser, and there's definitely something more than just the color depth causing artifacts in images. However, when I tried with the screen at 24-bit depth, the images did definitely look better, so it has something to do with it.