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.
Here are a few individual close-ups if you want a better look.
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||Black, cd/m2||White, cd/m2|
|Samsung Galaxy Nexus||0||112||∞||0||247||∞|
|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|