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 Pentax WG-3 and Olympus E-PL9 side-by-side from the front, back and top in their relative dimensions. Pentax WG-3 has external dimensions of 124 x 64 x 33 mm (4.9 x 2.5 x 1.3″) and weighs 230 g (0.51 lb / 8.11 oz) (including batteries). Olympus E-PL9 has external dimensions of 117 x 68 x 39 mm (4.61 x 2.68 x 1.54″) and weighs 380 g (0.84 lb / 13.40 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax WG-3 and the Olympus E-PL9. Pentax WG-3 is 4mm shorter and 6mm thinner than Olympus E-PL9 but it is also 7mm wider. As you can tell, actually this is not a fair size comparison since Pentax WG-3 has a built-in lens but Olympus E-PL9 doesn't. Once you put a lens on E-PL9, its thickness will increase significantly.
Here is the back view size comparison of the Pentax WG-3 and Olympus E-PL9.
Now lets look at the top view comparison of Pentax WG-3 and Olympus E-PL9.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax WG-3 is significantly lighter (150g ) than the Olympus E-PL9 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-PL9, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the WG-3, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the E-PL9.
LCD Screen Size and Features
Pentax WG-3 and Olympus E-PL9's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Olympus E-PL9 features a
Tilting screen where you can change the angle of the screen to make it easier to shoot from waist or over-the-head levels whereas the Pentax WG-3 has a fixed type screen which provides less flexibility in shooting positions compared to E-PL9.