Nikon L20 has a
10.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized CCD sensor . On the other hand, Olympus TG-5 has a
12.0MP (1/2. ) sized BSI-CMOS sensor and features TruePic VIII processor.
Below you can see the L20 and TG-5 sensor size comparison.
As seen above, Nikon L20 has a infx Larger sensor area than Olympus TG-5. 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.