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 VG-120 and Pentax Q10 side-by-side from the front, back and top in their relative dimensions. Olympus VG-120 has external dimensions of 96 x 57 x 19 mm (3.78 x 2.24 x 0.75″) and weighs 120 g (0.26 lb / 4.23 oz) (including batteries). Pentax Q10 has external dimensions of 102 x 58 x 34 mm (4.02 x 2.28 x 1.34″) and weighs 200 g (0.44 lb / 7.05 oz) (including batteries).
Below you can see the front-view size comparison of the Olympus VG-120 and the Pentax Q10. Olympus VG-120 is clearly the smaller of the two cameras. Its body is 6mm narrower, 1mm shorter and 15mm thinner than Pentax Q10. As you can tell, actually this is not a fair size comparison since Olympus VG-120 has a built-in lens but Pentax Q10 doesn't. Once you put a lens on Q10, its thickness will increase significantly.
Now lets look at the top view comparison of Olympus VG-120 and Pentax Q10.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Olympus VG-120 is significantly lighter (80g ) than the Pentax Q10 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 Q10, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Olympus VG-120 nor Pentax Q10 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 VG-120 and Pentax Q10's LCD screens have the same diagonal size of 3.00 inches.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.