The Nokia 6 video image quality is pretty good, but the bad low-light performance and the lack of an optical image stabilization doesn't help either.I don't know if the Nokia 6 comes with an electronic image stabilization (EIS), but from the video sample below, it seems that it doesn't because the video just isn't stable. Judging from some sample videos, the rear-facing camera produces good colors in available light with good exposure and sharp details, but nothing to get excited about. I was expecting more than just a middling image quality and better low-light performance from this phone.
Here is the video shot by RTS RealTechShow YouTube user that compared the Nokia 6 front and rear facing cameras versus the iPhone 7 Plus camera.
I have to admit that I personally liked the rendering of the Nokia 6 because it produces warmer colors and the greens just look much more pleasing to my eyes. However, the white balance can miss sometimes and I've seen that in some sample images.
Judging by the Nokia 6 sample videos, the autofocus speed is pretty good, although I believe that it performs well only in good light and the performance should drop quite significantly due to the sensor's bad low-light performance. Speaking of low light performance, the Nokia 6 just can't match the low-light performance of some of the upper mid-range smartphones that come with a faster aperture and with larger pixels. The Nokia 6 really performs admirably well in good lighting conditions, so if you shoot mainly in daylight or in a well-lit place, you can expect high quality images and videos. The main problem with the Nokia 6 rear camera is that the sensor has 1 micron pixels which limits the camera's capabilities.
I personally enjoy watching a relatively clean images and videos. I think that noise in videos is really disturbing to watch, it's just like it was shot in a retro style recording mode, I mean, everyone wants to be able to capture good videos not only in daylight, but in the afternoon and when the sun start fading away. In fact, some of my best videos were recorded in the "golden hour", sometimes in the early morning and sometimes in the late afternoon.
With a camera like the Nokia 6, you will always feel that you have to record a video before the evening comes because you know you won't be able to get very good video quality. It doesn't mean that you won't be able to shoot, you still get a good exposure if there is a strong ambient light source nearby, but just aware of the limitations. I remember shooting videos with my iPhone 5S which has a f/2.2 aperture lens and 1.5-micron pixels and it was just so frustrating shooting videos at night. just too much noise and with very little exposure, the video just seem too dark. I was always searching for a good place with enough light to capture the videos.
The f/2.0 aperture lens of the Nokia 6 does help in some way,but those tiny pixels just ruin it. I wish Nokia would have chosen to go with a 12MP or even 8MP sensor, I'm sure the low-light performance would have been great due to the larger pixels. The dynamic range is also quite limited due to the small pixels and I've seen that in the sample images and test videos that I've seen through the web. With good light source you still going to get good details in the shadows, but it's limited compared to mobile phone cameras that have much larger pixels.
So overall, you get a decent video quality with warm vivid colors, good exposure and autofocus, but as long as you record your videos in good lighting conditions. I think that it's a descent camera overall for the given price (as sold in China). It's also not fair to compare the Nokia 6 versus a high-end phone like the iPhone 7 Plus that costs three times as much. That being said, you probably going to get this video quality with most cheap phones out there that has a fast aperture. It's not that the Nokia 6 rear camera is special or something. I'm personally disappointed to see the Nokia 6 coming with such a not impressive specs. I personally want to have a rear camera on my future Nokia phone that isn't just yet another middling performing camera, this why I categorized my opinion in the disadvantage section - the overall video performance is just isn't enough for me and I was expecting more from Nokia. Using a 16MP for a small sensor is not a smart idea in my opinion.