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 Panasonic G100 and Pentax WG-3 GPS side-by-side from the front, back and top in their relative dimensions. Panasonic G100 has external dimensions of 116 x 83 x 54 mm (4.57 x 3.27 x 2.13″) and weighs 352 g (0.78 lb / 12.42 oz) (including batteries). Pentax WG-3 GPS has external dimensions of 125 x 64 x 33 mm (4.9 x 2.5 x 1.3″) and weighs 238 g (0.52 lb / 8.40 oz) (including batteries).
Below you can see the front-view size comparison of the Panasonic G100 and the Pentax WG-3 GPS. Pentax WG-3 GPS is 19mm shorter and 21mm thinner than Panasonic G100 but it is also 9mm wider. As you can tell, actually this is not a fair size comparison since Pentax WG-3 GPS has a built-in lens but Panasonic G100 doesn't. Once you put a lens on G100, its thickness will increase significantly.
Here is the back view size comparison of the Panasonic G100 and Pentax WG-3 GPS.
Now lets look at the top view comparison of Panasonic G100 and Pentax WG-3 GPS.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax WG-3 GPS is significantly lighter (114g ) than the Panasonic G100 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 G100, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the WG-3 GPS, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the G100.
LCD Screen Size and Features
Panasonic G100 and Pentax WG-3 GPS's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Panasonic G100 sports a
Fully Articulated screen which you can change the angle and position of the screen almost freely, making it possible to shoot from waist or over-the-head levels, and especially very useful for shooting selfies and video. Pentax WG-3 GPS's LCD screen is a fixed type which provides almost no flexibility in shooting positions compared to G100.