Final assessment
Josh and I both agree that the HTC One's camera is the weakest of the three. Its color reproduction is cooler and adds a blue cast to shades. It also overexposes more shots and conveys the least amount of detail. However, the One's low-light performance was pretty good, and in many instances, we'd be happy using a picture from the One in casual photo-sharing situations.
When it comes to the out-and-out winner, the tussle between the iPhone 5 and Samsung Galaxy S4 grows murkier. In well-lit photos, the choice for the "better" camera is a coin toss. The iPhone's slight underexposure captures the most detail across a scene, but the GS4 camera produced a lot of the photos we liked best.