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 VS20 and Sony NEX-3 side-by-side from the front, back and top in their relative dimensions. Pentax VS20 has external dimensions of 111 x 61 x 38 mm (4.37 x 2.4 x 1.5″) and weighs 235 g (0.52 lb / 8.29 oz) (including batteries). Sony NEX-3 has external dimensions of 117 x 62 x 33 mm (4.61 x 2.44 x 1.3″) and weighs 297 g (0.65 lb / 10.48 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax VS20 and the Sony NEX-3. Pentax VS20 is 6mm narrower and 1mm shorter than Sony NEX-3 but it is also 5mm thicker. As you can tell, actually this is not a fair size comparison since Pentax VS20 has a built-in lens but Sony NEX-3 doesn't. Once you put a lens on NEX-3, its thickness will increase significantly.
Now lets look at the top view comparison of Pentax VS20 and Sony NEX-3.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax VS20 is significantly lighter (62g ) than the Sony NEX-3 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 NEX-3, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Pentax Optio VS20 nor Sony Alpha NEX-3 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
Pentax VS20 and Sony NEX-3's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Sony NEX-3 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 VS20 has a fixed type screen which provides less flexibility in shooting positions compared to NEX-3.