Do you have an iPhone 6 Plus which takes blurry photos? If so, then according to Apple you could be owed a fix, due a faulty internal camera component.
Apple’s website notes that the issue in question affects a number of iPhone 6 Plus handsets sold between September 2014 and January 2015. The problem relates to the the iSight camera on the back of the phone, rather than the “selfie” camera at the front.
Apple will replace these cameras for free, provided that customers take the affected iPhone 6 Plus along to an Apple Store, authorized service provider, or contact technical support to arrange a swap. Customers should go through Apple rather than their wireless carrier, since the latter are unable to deal with the issue.
To see if you have an affected iPhone 6 Plus you can check the serial number on your device at this webpage. Your serial numbers can be discovered by going to the “Settings menu > General > About” on your iPhone. The number is also printed on the box your iPhone camera in.
I have had one of the blurry camera iPhone 6 Plus devices, although I replaced it early on. Not all photos were blurry, although the lens failed to autofocus and could only take properly focused photos of close-up subjects.