It's no secret really. A smaller f-stop number allows for a larger aperture which lets more light in. What Nokia has done that is brilliant is to realize that it had captured this niche and has taken advantage of it by promoting the ability of its phones to take quality shots where other phones might have left you in the dark. And with Optical Image Stabilization, others will think that you used a tripod when shooting video even though you actually had the phone in your hand the whole time.
Now Steve Ballmer and crew have released an infographic stating that we spend half our lives in the dark. And with 70% primarily using their handset to take pictures, a snapper that lets you shoot in the dark is needed. That camera, according to Microsoft, is the Nokia Lumia 928. The phone is an exclusive in the U.S. to Verizon.
Microsoft promotes low-light photography
source: Microsoft via WMPoweruser