Now in HD: Galaxy Nexus vs. Optimus LTE screen shootout

Introduction

Done pushing megapixels and well into pixel popping, still the good old numbers game. HD screens are the next big thing and they'd better enjoy it while it lasts, with quad-core around the corner and all.
Anyway, is it just another number to brag about or is there really something to the "HD" label. To find out, we're looking at two of the first smartphones with 720p screens - the Samsung Galaxy Nexus and the LG Optimus LTE (very similar to the LG Nitro HD).


The two have similarly sized screens - 4.65" for the Nexus and 4.5" for the Optimus - and both push pixel density over 300ppi, the threshold above which eye-watering magic starts to happen.
They are from two different worlds though. The LG Optimus LTE uses a traditional three-subpixel matrix for its AH-IPS LCD display (a.k.a. True HD IPS), while the Galaxy Nexus has only two subpixels per pixel (called PenTile) in its Super AMOLED matrix.
Both have plenty to brag about, but they won't get away with just judging them by their sharpness. LG are shaping up as the standard-setter in display brightness, so that's something to look out for. Viewing angles (a typical weak spot for LCDs) is another thing they seem to have addressed.
There's a lot to test, so let's not waste any more time. We'll be doing both scientific measurements (trying to break down display performance into hard numbers) as well as providing subjective opinions (as hunting for the better spec doesn't always result in the best experience).
Side note: For those of you getting acronym sickness, AH-IPS LCD stands for "Advanced High-Performance In-Plane Switching Liquid Crystal Display". AMOLED is short for "Active Matrix Organic Light-Emitting Diode". 

Display image quality

What is "image quality" made of? Size, resolution and pixel density are obviously important, but there's also color rendering, brightness and contrast. Viewing angles and the reflectivity of the screen are essential for the outdoor performance.
Pixel density and sharpness
As we said, the two phones have screens that are nearly the same size - the 0.15" difference is negligible. That works out to about 7 % more real estate in favor of the Nexus, but at the cost of pixel density - 316ppi vs. 326ppi for the Optimus LTE. Both qualify for the unofficial "retina display" label (a marketing term coined by Apple).
That's not the whole story though - the screen of the Samsung Galaxy Nexus only has two thirds of the total subpixels of the LG Optimus LTE. That reduces the sharpness of the image and color rendering may suffer as well.
It turns out that it isn't much of an issue but it's something you can see if you look closely. For example, curves appear slightly jagged on the Nexus screen, which is not the case in the Optimus LTE. You might also spot a slight crosshatch pattern that's typical of PenTile when looking at solid colors bordering black areas - especially red and blue colors, since each pixel in the PenTile arrangement has a green subpixel.
Another way to spot is to look at very fine textures - like the strawberries or the yellow leaves in our test picture.

Side-by-side comparison of macro shots - Samsung Galaxy Nexus vs. LG Optimus LTE
Here are a few individual close-ups if you want a better look.

LG Optimus LTE • Samsung Galaxy Nexus
However, the image processing applied by the gallery seems to be contributing more to the difference here than the type of screen matrix. LG's gallery tends to sharpen the images. Look at the doubled borders between the gray bars and the borders around the dark areas of the squares - those aren't present in the original image. The Nexus gallery does some sharpening too, but it's less prominent.
It's nothing major and you really need to be looking from much closer than you normally would, but the AH-IPS LCD of the Optimus LTE has an advantage here.
Brightness and contrast
When it comes to brightness, it's another win for the Optimus. The Galaxy Nexus posted some really poor brightness results. And although it's not really as bad as at the numbers suggest, the Galaxy Nexus screen does look dim even at the maximum brightness setting.
We measured 247 nits with the brightness maxed up, while the Optimus LTE scored 428 nits. It seems to be limited in software as the display should ideally hit 600 nits at maximum. The image gallery and browser use different settings than the rest of the apps, so we downloaded a third party gallery, which posted a slightly higher result but the brightness of the screen was exactly equal to that of the Galaxy Note.
The Super AMOLED screen starts making back lost ground when we get to contrast. It's theoretically infinite (though you'll need to be in a perfectly dark room, so ambient light doesn't interfere), but the contrast of the AH-IPS LCD of the Optimus LTE is quite good too.
Here's how the two compare in terms of brightness and contrast against the competition. Note that we don't have readings for the Optimus LTE at 50% brightness - even with Automatic brightness turned off, the phone used the exact same brightness levels in the gallery when set to 50% and to 100%.
  

Display test	50% brightness			100% brightness
	Black, cd/m2	White, cd/m2	Contrast ratio	Black, cd/m2	White, cd/m2	Contrast ratio
Samsung Galaxy Nexus	0	112	∞	0	247	∞
HTC Rhyme	0.43	265	609	0.58	402	694
HTC Explorer	0.26	201	763	0.47	358	755
HTC Sensation	0.21	173	809	0.61	438	720
HTC Incredible S	0.18	162	908	0.31	275	880
Samsung Omnia W	0	118	∞	0	358	∞
LG Optimus 2X	0.23	228	982	0.35	347	1001
LG Optimus LTE	-	-	-	0.39	428	1101
Sony Ericsson XPERIA Arc	0.03	34	1078	0.33	394	1207
Samsung I9100 Galaxy S II	0	231	∞	0	362	∞
Samsung Galaxy Note	0	287	∞	0	429	∞
Apple iPhone 4S	0.14	205	1463	0.52	654	1261

Color rendering and accuracy Color rendering is an area where AMOLEDs typically perform very well and the Galaxy Nexus does indeed offer vibrant colors, if you don't mind the oversaturation. TouchWizz-skinned Samsung phones usually have a setting for the color rendering, but it's not available in the purebred Android Galaxy Nexus. The Optimus LTE resists the temptation to boost saturation and offers more accurate colors. Intertek, an international certification company, measured the accuracy of the AH-IPS display and fount it was three times more accurate (that is the difference between the original color and the color displayed was three times smaller) than the Super AMOLED Plus of the Samsung Galaxy S II. There are no numbers for the Super AMOLED of the Galaxy Nexus, but they should be similar to those for the S II (or worse as it doesn't have a full set of subpixels per pixel). There's another factor when talking about color accuracy - color temperature. The Super AMOLED screen shows warmer colors, while the AH-IPS is much closer to true white. LG have something called Mobile Graphics HD Engine, which controls the colors - and it seems to be doing a good job. Viewing angles Viewing angles is one area where AMOLED displays usually excel and the Galaxy Nexus is no exception. There's a slight color shift when viewed at an angle but contrast remains unchanged. IPS tries to fix the viewing angle problems of typical LCDs and the 4.5" AH-IPS display on the Optimus LTE is one of the best we've seen. You can look at it at extreme angles and image remains basically unchanged. There's a slight shift of color depending on the angle, but contrast remains unaffected. Overall, as far as viewing angles are concerned the two displays are practically tied. LG Optimus LTE and Samsung Galaxy Nexus viewed at an angle Reflectivity We mentioned the importance of screen reflectivity a couple of times already. It affects both contrast, as light reflects off the screen (including the black areas), and outdoor visibility as glare might make things impossible to read off the screen. Obviously, strong enough light will defeat both displays, but in general the Samsung Galaxy Nexus holds up better. Its screen reflects noticeably less light and, despite being dimmer, remains more legible. Reflectivity comparison: Optimus LTE vs. Galaxy Nexus Here's a video that showcases the videos and the reflectivity of both screen.

Final words

High-quality AMOLED displays used to be unbeatable in providing the best image quality. The depth of blacks, the rich colors and impeccable viewing angles add up to an experience that's very hard to resist. LG have gone to great lengths to change our minds though. The 4.5" AH-IPS display on the Optimus LTE (the Nitro HD too) deals with the weak points of the LCD technology and beats the 720p Super AMOLED on more than a few occasions. The biggest advantage is brightness - it takes a properly lit screen to fully enjoy the actual image quality. Graphics are smoother than PenTile (readily evident in diagonal lines and curves), plus the white balance and color rendering are more accurate. The Super AMOLED on the Samsung Galaxy Nexus offers the unbeatable blacks and slightly better viewing angles. It has the upper hand in outdoor performance due to its lower reflectivity. It's very hard - impossible almost - to say which screen you should go for. Screens cannot be chosen separately from the phone and the difference between those two displays isn't big enough to tip the scales either way. The rest of the hardware and the software are bigger factors. Plus neither the AMOLEDs nor the LCDs are all born equal. There are AMOLED units brighter than the Galaxy Nexus and LCD screens with better contrast than the LG Optimus LTE. Those screens have issues elsewhere though, so you really can't have it all. The important conclusion to draw from this test is that AMOLEDs aren't always superior to LCDs - you can go for an AH-IPS LCD phone if the rest of the specs tick the right boxes and you'll still have one of the best screens on the market.