Google Pixel phones suffer from lens flare issue. This issue was reported by many reviewers who tested the camera, including DxOMark. The camera produces a halo effect when you shoot at a specific angle. This glaring issue brought up after some people noticed that there are not the only ones who have this issue. Some people thought that maybe it's only their phone, but some reviewers even checked a few Pixel devices and found out that the problem persists.
The defect was first reported on Reddit and also on Google Pixel User Community Forums. When you shoot at a specific angle, you can see a halo appearing at a section of the frame. It's very annoying to watch. Sometimes is appears at the bottom of the frame, sometimes is appears like a circle in the middle of the frame. Since that report, there were many people reporting the same issues and uploading their own photos to twitter showing the same lens flare problem.
Halos, flare, and glare happen because of the way the light hit the lens. Google has acknowledged this lens flaring issue and this thing affects every Pixel phone. From what I've read on Phandroid, Google plans to release a software patch with an algorithm that will eliminate the halo from the image. So this is indeed a hardware issue, but it would be good if Google can solve it by just updating it on the software side. It can't obviously replace all the Pixel phones for everybody, so this is a good alternative solution.
I'm sure some people will find it a bit irritating knowing that there is some defect in their Google Pixel camera, nobody love to hear that the hardware has a defect. Some people also mentioned that the problem also exists in video recording, and don't know how Google can fix this for videos.
I've read the post on Pixel User Community. There a guy from Google mentioned that lens flare is a property of all lenses. So some lenses are more prone to it than others. I personally think that wide-angle lenses are more prone to that due to their lens design, but I am not a professional photographer nor I am qualified optometrist :)
Another thing mentioned in his post is that Isaac said that you will need to shoot in the HDR+ photo mode in order to make it work. I thought that it will work by default, but apparently in order for this to work, the image should go through a processing procedure that the default image capture doesn't go through. If it went through these processes, I believe it would have hurt the camera's performance in some degree. Anyways, there are many images on that post that demonstrate the issue, so check them out.
Here's a video posted by Phandroid regarding this issue.
Click here to see a sample image that show the problem. Until this problem is solved, it's still a major disadvantage. For more information visit the Pixel User Community and the post on phandroid.com.