Nokia Lumia 720 is a Windows Phone device with 6.7MP Camera + Carl Zeiss optics, Autofocus and LED Flash. Microsoft Lumia 730 on the other hand is a much updated Windows Phone device with 6.7MP Camera + Carl Zeiss optics, Autofocus, Face detection, Panorama and LED Flash. The 720 has a sensor size of 1/3.6” and the 730 has got 1/3.4” for itself.
The photo below shows the difference between using a Lumia 720 and Lumia 730 to take pictures. The difference is clear!
A thousand words can be embedded in a picture right? I’ve done enough talking. See for yourself!

Moral lesson: It is not all about Mega-pixels.
What do you think?