The LG V10 has the widest aperture of the four phones (f/1.8), while the Nexus 6P (f/2.0) impressed us when we updated our Photo quality comparison tool, so those are the two favorites this round. The Galaxy Note5 (f/1.9) won't go down without a fight, while from past experience we know the Meizu PRO 5 (f/2.2) does not like the dark).
The LG V10 loses some detail to its noise reduction system, but it managed to resolve some detail that the Nexus could not. Note that we shot a fairly static scene and the V10 dropped the shutter speed to 1/11s, which will cause blurring issues if there are people moving around.
The Huawei Nexus 6P maintained a relatively fast shutter speed, 1/20s, and let the ISO go higher. The end result is very high quality, though its penchant to underexpose shadows comes back to bite it.
The Samsung Galaxy Note5 photo seems soft (we picked the best of five, some of which were taken after a tap to focus). The noise reduction is the culprit - you can see noise in the sky (especially on the LG), but not on the Note5. Unfortunately, a lot of the sharpness went out with the noise.
Then there's the Meizu PRO 5. The narrow aperture and strong noise reduction didn't give it a fighting chance.
Winner: LG V10. It's situational, but under ideal conditions you'll get the best quality out of the V10.
Runner-up: Huawei Nexus 6P. The faster shutter speed of the Nexus will allow it to handle moving objects better, but the darker parts of the image are basically pure black.
Third place: Samsung Galaxy Note5. There's a choice: noise-free image or sharp image. Samsung chose the first and if you never zoom in on the image, it's a decent choice.
2160p video camera
The strong low-light performance of the LG V10 extends to video too. There's a lot of noise, but the camera managed to keep a reasonable amount of detail and color rendering looks okay.
The Huawei Nexus 6P meanwhile was let down by its processing. The colors are way off and that's only where the over the top contrast didn't crush the color completely.
The Samsung Galaxy Note5 once again turns in a soft image, but it handles colors better and actually maintained details lost by the Nexus.
The Meizu PRO 5 had difficulty finding the right focus (you can see in the included sample that we had to tap to get it to refocus). The image quality is not great either, noise combined with very strong compression does that to a video.
Here are the short videos we shot for this test. We had to keep them short as we shot at dusk, any longer and the light would have changed too much between the first and the last phone.
Winner: LG V10. We pushed the camera to its limit and it handled itself well. There's a lot of noise left over in the video, but the exposure and colors are good.
Runner-up: Samsung Galaxy Note5. We have to give this one to the Note5, the Nexus really the mark on the colors and darker areas are ruined by contrast.
Third place: Huawei Nexus 6P. The hardware is capable, but the image processing does more harm than good.
1080p video camera
The LG V10 does what it did in the 2160p test, finding the best balance of exposure, color rendering and noise reduction.
At the lower resolution, much of the softness in the Samsung Galaxy Note5 videos is gone so they are much more competitive with the V10, but its Korean neighbor still produced the better image.
The Huawei Nexus 6P repeated its mistakes from last time, with issues with color and in dark areas. The Meizu PRO 5 video is passable, but very dark.
And here's the batch of low-light videos shot at 1080p. We had stabilization turned off for this (where the option was available), so that each phone had only the dark to worry about.
Winner: LG V10. Different resolution, same results - the sharpest image, with good detail and colors of the four.
Runner-up: Samsung Galaxy Note5. Even at 1080p the work of the noise reduction is noticeable. At least videos aren't overly dark and with distorted colors like the Nexus videos.
Third place: Huawei Nexus 6P. What it says above - contrast turns dark areas into pure black and decimates colors, the hues that survive are exaggerated.