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 Nikon S30 and Olympus E-P3 side-by-side from the front, back and top in their relative dimensions. Nikon S30 has external dimensions of 102 x 65 x 40 mm (4.02 x 2.56 x 1.57″) and weighs 214 g (0.47 lb / 7.55 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 Nikon S30 and the Olympus E-P3. Nikon S30 is 20mm narrower and 4mm shorter than Olympus E-P3 but it is also 6mm thicker. As you can tell, actually this is not a fair size comparison since Nikon S30 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 Nikon S30 and Olympus E-P3.
Now lets look at the top view comparison of Nikon S30 and Olympus E-P3.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Nikon S30 is significantly lighter (155g ) 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 S30 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 Nikon S30's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.