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 Casio EX-H15 and Olympus E-M10 III side-by-side from the front, back and top in their relative dimensions. Casio EX-H15 has external dimensions of 101 x 60 x 28 mm (3.98 x 2.36 x 1.1″) and weighs 161 g (0.35 lb / 5.68 oz) (including batteries). Olympus E-M10 III has external dimensions of 122 x 84 x 50 mm (4.8 x 3.31 x 1.97″) and weighs 410 g (0.90 lb / 14.46 oz) (including batteries).
Below you can see the front-view size comparison of the Casio EX-H15 and the Olympus E-M10 III. Casio EX-H15 is clearly the smaller of the two cameras. Its body is 21mm narrower, 24mm shorter and 22mm thinner than Olympus E-M10 III. As you can tell, actually this is not a fair size comparison since Casio EX-H15 has a built-in lens but Olympus E-M10 III doesn't. Once you put a lens on E-M10 III, its thickness will increase significantly.
Here is the back view size comparison of the Casio EX-H15 and Olympus E-M10 III.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Casio EX-H15 is significantly lighter (249g ) than the Olympus E-M10 III 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-M10 III, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Casio Exilim EX-H15 nor Olympus OM-D E-M10 Mark III 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
Casio EX-H15 and Olympus E-M10 III's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Olympus E-M10 III 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 Casio EX-H15 has a fixed type screen which provides less flexibility in shooting positions compared to E-M10 III.