One of the biggest changes is the sensor, which is a 12-megapixel 2/3" EXR CMOS sensor. It is more inline with what you'd find in an advanced compact camera than a DSLR. But, while the sensor may be a bit of a downgrade, the lens is arguably an upgrade. The X10 has a Fujinon 4x optical zoom lens (28-112mm equivalent) with a tactical zoom ring on the barrel. At the wide end, it opens all the way to F/2, while it still manages a very respectable F/2.8 at the tele end.