I'm a big proponent of the idea that the best camera is the one that's with you. I also try to promote calm and realistic expectations of what smartphones can achieve, given their size and one-size-fits-all nature. The dark intersection between these two maxims is a dense and cruddy-looking purple haze.
I'm not sure when I first noticed it, but once you see it, you can't unsee it. Many others are seeing it, too: AndroidCentral forum posters, XDA developer posters, Reddit users, Now the purple haze is my primary thought when I'm shooting or editing photos taken on my phone. Here are some Cheryl's cookies, lost inside the haze (though still delicious).
The HTC One I carry with me was touted in early reviews for its unique camera: only 4 megapixels, but those pixels were "Ultrapixels," large and supposedly superior at capturing images in low-light situations. Here's how Computerworld colleague JR Raphael described the HTC One camera in a FAQ post
Aided by a new dedicated "ImageChip" and retooled light sensor, the camera is said to be able to absorb three times as much light as a typical smartphone camera setup. The resolution is limited to 4 megapixels, but HTC insists the pixels are far more detailed and high-quality than what you'd get with other comparable phones.
Shooting in low-light conditions, however, and seemingly with any kind of notable light source outside the frame, you get quite a bit of purple "noise" in your shot. Sometimes this happens in decent lighting, too. See my friend's little guy below, peeking at me while I'm in a small room with a 60-watt compact fluorescent bulb at roughly eye level.
So my smartphone isn't as good at preventing noisy shots as a DSLR, and an otherwise great phone has a notable flaw. I bring this up not to hit you with dog and adorable kid shots (well, not _only that reason), but to point out that getting to know a phone and all its quirks takes a while. It takes a good long while longer than most reviewers get to render judgement on a phone. And it takes longer than your friends who rush out and buy the latest models of everything will have before they recommend the same models to you.
Oddly enough, the One's tendency toward purple was found out in an in-depth review of HTC One camera at Digital Photography Review.
The same picture is ideal to demonstrate another one of the One's flaws: purple fringing. If you look closely at the reflection of the sun on the water you can see very strong fringing which almost adds a purple tint to the lake surface.
A review of the HTC One at The Verge doesn't mention any purple shading or low-light noise, at least specifically. In fact, The Verge reviewer notes that, "Thanks to its optical image stabilization (the One) can basically see in the dark and take steady photos." The same goes for a Gizmodo side-by-side comparison with the iPhone 5 and Lumia 920. A CNET HTC One review dials back the "magic low-light camera" pabulum, but also misses the purple tint entirely. One commenter, though, goes right at the purple haze.
The forums and comment discussions I've seen pertaining to the HTC One suggest that more than a few have asked and received replacement phones from HTC, and that some of them then see an improvement in the "purple haze" issue—and some get the same phone they had before back. The release of Android 4.3 for the HTC One was purported to have a camera fix, but no dice. The way that the One takes photos might just create some strange purple-ish hues.
It's worth noting that the iPhone 5 was reported to have a similar purple-frame-light issue, and Apple's response was, basically, yeah, cameras pointed at bright lights in low-light conditions are going to produce weird photos.
One make-do fix I've taken up is switching from using the official HTC camera to using alternative camera app Focal, which puts the ISO setting more front and center. Your smartphone camera will, by default, ratchet up its ISO number to get more light in dark situations; you can manually dial it down to prevent some of the purple tint/haze.
Most camera shots come out fine—not breathtaking, not like a Prince video, just fine. This purple haze has just given me pause when it comes to trusting those who believe that smartphones will eventually replace All The Things we might ever use to capture or connect things. They are thin, multi-tasking computers, and though they have come a long way, they are not quite cameras. At least mine is not.
Note: I have seen the newer iPhones take some fantastic shots. I think Apple puts pretty much the best possible camera in their own thin, multi-tasking devices. Thank you for reading this note.