Ricoh CX3: 10 megapixels, with back-illuminated sensor

I’m just wrapping my head around CMOS and you spring this on me? This Ricoh CX3 is a 10-megapixel shooter with 720p video recording and “Pets” scene mode. But what the heck is a back illuminated sensor?

DPreviewHas the full release but you’re basically looking at better low-light performance with the back-lit CMOS. I honestly don’t quite get how it works, but it seems to improve low-light performance greatly by reducing the distance light has to travel to the sensor.

* The back-illuminated 10 megapixel CMOS sensor significantly increases shooting performance in low-light scenes.
* The CX3 uses the noise reduction algorithm introduced on the GR DIGITAL III. Performing noise reduction processing on the signal immediately after it is output by the CMOS sensor makes it possible to reduce noise while maintaining resolution, tone characteristics, and saturation.
* The noise reduction level can be specified as Off, Auto, Weak, Strong, or MAX. By specifying MAX, it is possible to do sophisticated variance-estimation type noise reduction processing in which the sensor image data’s noise variance is analyzed and the optimum processing is done for each region.

Here’s a bunch of info on back-lit/illuminated sensors if you’re interested. It seems to move the sensor closer to the lens rather than making it pass through a screen of wires.