Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Canon ELPH 150 IS and Olympus SZ-31MR iHS side-by-side from the front, back and top in their relative dimensions. Canon ELPH 150 IS has external dimensions of 95 x 57 x 24 mm (3.74 x 2.24 x 0.94″) and weighs 142 g (0.31 lb / 5.01 oz) (including batteries). Olympus SZ-31MR iHS has external dimensions of 106 x 69 x 40 mm (4.17 x 2.72 x 1.57″) and weighs 226 g (0.50 lb / 7.97 oz) (including batteries).
Below you can see the front view size comparison of Canon ELPH 150 IS and Olympus SZ-31MR iHS. Canon ELPH 150 IS is clearly the smaller of the two cameras. Its body is 11mm narrower, 12mm shorter and 16mm thinner than Olympus SZ-31MR iHS.
Now lets look at the top view comparison of Canon ELPH 150 IS and Olympus SZ-31MR iHS.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Canon ELPH 150 IS is significantly lighter (84g ) than the Olympus SZ-31MR iHS which may become a big advantage especially on long walking trips.
Unfortunately neither Canon PowerShot ELPH 150 IS (IXUS 155) nor Olympus SZ-31MR iHS provides any type of weather sealing in their body, 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
LCD Screen Size and Features
Olympus SZ-31MR iHS's 3.00" LCD screen is slightly larger than Canon ELPH 150 IS's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.