Maybe not the sensor so much as the lens![]()
It's not super obvious but look at the center.
One looks bulging and blue and the other recessed and less obviously blue
But I'll post another sample pic comparison that will end the debate in a bit.
In lower light, the quality differences are greater
Sapphire Crystal
Although the surface of the iSight camera is as clear as glass, its not made of glass. Its actually sapphire crystal, whose hardness is second only to diamond on the scale of transparent materials. That means the surface of the lens is far less likely to scratch.
http://www.apple.com/iphone/design/