Size and weight are big decision factors when you are trying to find the ideal camera for your needs.
In this section, we are going to illustrate the Canon D10 and Olympus E-P3 side-by-side from the front, back and top in their relative dimensions. Canon D10 has external dimensions of 104 x 67 x 49 mm (4.09 x 2.64 x 1.93″) and weighs 190 g (0.42 lb / 6.70 oz) (including batteries). Olympus E-P3 has external dimensions of 122 x 69 x 34 mm (4.8 x 2.72 x 1.34″) and weighs 369 g (0.81 lb / 13.02 oz) (including batteries).
Below you can see the front-view size comparison of the Canon D10 and the Olympus E-P3. Canon D10 is 18mm narrower and 2mm shorter than Olympus E-P3 but it is also 15mm thicker. As you can tell, actually this is not a fair size comparison since Canon D10 has a built-in lens but Olympus E-P3 doesn't. Once you put a lens on E-P3, its thickness will increase significantly.
Here is the back view size comparison of the Canon D10 and Olympus E-P3.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon D10 is significantly lighter (179g ) than the Olympus E-P3 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on E-P3, the total kit will weigh much higher.
Weather Sealing
With its weather-sealed body, we believe that the D10 has a big advantage over the E-P3 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Olympus E-P3's 3.00" LCD screen is slightly larger than Canon D10's 2.5" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.