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 I-10 and Olympus E-PL9 side-by-side from the front, back and top in their relative dimensions. Pentax I-10 has external dimensions of 101 x 65 x 28 mm (3.98 x 2.56 x 1.1″) and weighs 153 g (0.34 lb / 5.40 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 I-10 and the Olympus E-PL9. Pentax I-10 is clearly the smaller of the two cameras. Its body is 16mm narrower, 3mm shorter and 11mm thinner than Olympus E-PL9. As you can tell, actually this is not a fair size comparison since Pentax I-10 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 I-10 and Olympus E-PL9.
Now lets look at the top view comparison of Pentax I-10 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 I-10 is significantly lighter (227g ) 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
Unfortunately neither the Pentax Optio I-10 nor Olympus PEN E-PL9 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 Compact Cameras with Weather Sealing Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Olympus E-PL9's 3.00" LCD screen is slightly larger than Pentax I-10's 2.7" screen.
In addition to the size advantage, Olympus E-PL9 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, Pentax I-10 has a fixed type screen which provides less flexibility in shooting positions compared to E-PL9.