The update has started rolling out globally and a Dutch Sony Xperia Z1 owner showed off some shots showing the difference in the quality of photographs taken before and after the update. As you can see, the update allows the camera to capture more detail, even in shadows. You should also notice the improved color reproduction and contrast.
The rear snapper on the phone is 20.7MP with an f/2.0 aperture that allows for clear photographs even in low-light conditions. With a 1/2.3 inch sensor and a Sony G lens, the firmware update helps the camera on the Sony Xperia Z1 come closer to reaching its potential.
source: XDA via GSMArena