There were some reports concerning the purple haze effect on some pictures taken with the iPhone 5; Apple decided to answer this concern with a support document that says the behavior is normal and a common one at that. Consumer reports took the iPhone 5 and other phones to their labs to conclude that, under the same circumstances, the effect is visible on the iPhone 5 as well as on the Galaxy S III or other phones.
The explanation is very simple and everyone with basic photography knowledge knows about lens-flare. Of course, lenses can be coated to a certain degree to reduce the effect but it is definitely present even on high end dSLR cameras (the lens hood is an accessory which tries to eliminate this issue when used on professional gear).
The problem appears “only when a bright light source, such as the sun appears in the frame of the photo or just outside it”. We’d add to that: “at a certain angle”. In conclusion, the iPhone 5 does indeed suffer from this purple haze problem but “it didn’t do so in any more pronounced a fashion than did the iPhone 4S or two Android-based smart phones, the Samsung Galaxy S III and Motorola Droid Razr Maxx, when we tested those under the same conditions”, says Consumer Reports.
Source: Consumer Reports