Camera black screen
Both cameras show black screen on iPhone 6 Plus is 9.2.1!
any fix?
iPhone 6 Plus, iOS 9.2.1
The cameras are dependent on each other at the hardware level. Often if one fails, then you can do a 'reset all settings' (not 'erase all settings'!) and figure out which one is the problem.
Another problem is that if you are close to your device storage limit, the camera app will not work since there is no space to store the picture.
As always, if your phone is in warranty, head to the Apple store.