Ricoh WG-6 has a 20.0MP 1/2.3-inch (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Canon 40D has a 10.0MP APS-C (22.2 x 14.8 mm ) sized CMOS sensor .
Ricoh WG-6's sensor provides 10MP more than Canon 40D's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the WG-6 and 40D sensor size comparison.
![Ricoh WG-6 vs Canon 40D Sensor Size Comparison]()
Sensor Size and Resolution Comparison image of Ricoh WG-6 and Canon 40D Cameras
As seen above, Canon 40D has a 11.7x Larger sensor area than Ricoh WG-6. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.