HTC is claiming that the UltraPixel camera on the HTC One will be able to capture 300 percent more light than competitors. You can shoot 1080p HD videos, HDR videos and there's a single LED flash for even better low-light shooting.
^ Is it comparable to sony xperia z 13mp cam ?
I've been in the camera bix for years and one thing is for sure, if you pack more dots into a smaller area the dots are then smaller. Less surface area means less light hits it and therefor less color spectrum capture and less light band capture. The reason SLR cameras can hit the higher pixels is due to the CCD size. The CCD is WAY bigger in the SLR than any cell phone so it can capture more color spectrum and more light bands.
I for one think that the camera in the HTC One will really stun people when they actually use it next to their old phone.