iPhone 5S camera v 6

so you can buy the 6s, why else?

 

That's just more or less lens flare. Maybe a finger smudge was on the sapphire crystal on the 6 to flare the lights like that. Or because they are two different angles as well can change how the light can flare on the lens. But overall the 6 image is better than the 5s image you've provided. (Huge difference in the players and everything else in the image.)

 

Possible moisture between the sapphire crystal and lens? Your second image is brutal and would suggest that with how foggy it looks.

I just tested my iPhone 6 and not getting any crazy flare. So it's definitely not an iPhone 6 issue at all and more just an isolated to your specific phone.

I would take it into an Apple Store and have it replaced because that for sure isn't normal.

 

I once had this issue with my 4. Went to the Apple Store, they cleaned the lens (was easy to remove the back cover with the 4), perfect afterwards.

 

I think this is the thing to do. It should, hopefully, be an easy cure.

 

the camera on the 6 sucks compared to the 5 and 5s.

http://forums.macrumors.com/threads...e-consistently-good-photos-with-my-6.1790221/

 

It doesn't suck compared to the 5 and 5s. It's actually better. What sucks is the amount of noise reduction is getting defaulted.

The reason (the main complaint in the thread you linked) backgrounds are looking "terrible" on the 6 vs 5 is because the 6 has a larger aperture lens than the 5. That means shallower depth of field (dof). That means smaller plain of "in focus". So with the 6's shallower depth of field and heavy noise reduction applied, gives the illusion of "worse".

Non of this has anything really to do with the way out of normal lens flaring going on with the OP's phone.