I would like to share a good article on 4/3 sensor goto http://www.wrotniak.net/photo/43/sensor-size.html Interesting pics taken from www.wrotniak.net (Viewfinder Size Difference) (Sensor Size) Interesting summary by wrotniak on the sensor:- --------- To sum things up, size-wise at least: 1.All three most common types of DSLR sensors (APS-C, Foveon/Sigma, Four Thirds) have practically the same size; therefore any discussions of differences between them due to the size are groundless and just demonstrate that someone did not bother to check the numbers. 2.The full-frame 35-mm (or 135-type, using the old film terminology) sensors are roughly twice that size (linear) or four times (area). 3.The smaller (2/3") sensors are approximately half that size (linear), or 1/4 of the area (the difference between those and 1/1.7" or 1/1.8" is, again, insignificant). --------------