Shortly after the iPhone 5 was released, some users began noticing a purple flare or halo on their photos when the camera is pointed at a bright light source. As tends to be the case, the issue only appears to be affecting some users and it certainly hasn’t attracted as much attention as the issues associated with Apple’s Maps app.
A forum thread over at Anandtech dives pretty deep into how the purple halo effect comes about and how one might avoid it. And the video below gives you a general idea as to what people are complaining about.
All that said, Apple this weekend issued a public support document addressing the issue following up on an email Apple’s support team sent to Gizmodo wherein they described the behavior as normal.
A purplish or other colored flare, haze, or spot is imaged from out-of-scene bright light sources during still image or video capture.
Most small cameras, including those in every generation of iPhone, may exhibit some form of flare at the edge of the frame when capturing an image with out-of-scene light sources. This can happen when a light source is positioned at an angle (usually just outside the field of view) so that it causes a reflection off the surfaces inside the camera module and onto the camera sensor. Moving the camera slightly to change the position at which the bright light is entering the lens, or shielding the lens with your hand, should minimize or eliminate the effect.