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 Olympus E-PM2 and Samsung NX300M side-by-side from the front, back and top in their relative dimensions. Olympus E-PM2 has external dimensions of 110 x 64 x 34 mm (4.33 x 2.52 x 1.34″) and weighs 269 g (0.59 lb / 9.49 oz) (including batteries). Samsung NX300M has external dimensions of 122 x 64 x 41 mm (4.8 x 2.52 x 1.61″) and weighs 331 g (0.73 lb / 11.68 oz) (including batteries).
Below you can see the front-view size comparison of the Olympus E-PM2 and the Samsung NX300M. Olympus E-PM2 is 12mm narrower and 7mm thinner than Olympus E-PM2 but they have the same height of 64mm.
Now lets look at the top view comparison of Olympus E-PM2 and Samsung NX300M.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Olympus E-PM2 is significantly lighter (62g ) than the Samsung NX300M which may become a big advantage especially on long walking trips.
Also keep in mind that body weight is not the only deciding factor when comparing two interchangeable camera bodies, you also have to take into account the lenses that you will be using with these bodies. Since Samsung NX300M has an APS-C sized sensor and Olympus E-PM2 has a smaller Four Thirds sensor, Olympus E-PM2's lenses for a similar focal length and aperture will generally be lighter and smaller than the Samsung NX300M lenses.
Weather Sealing
Unfortunately neither the Olympus PEN E-PM2 nor Samsung NX300M provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Samsung NX300M's 3.30" LCD screen is slightly larger than Olympus E-PM2's 3" screen.
In addition to the size advantage, Samsung NX300M LCD screen also has a
Tilting feature where you can change the angle of the screen to make it easier to shoot from waist or over-the-head levels. On the other hand, Olympus E-PM2 has a fixed type screen which provides less flexibility in shooting positions compared to NX300M.