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 Q-S1 and Panasonic GM1 side-by-side from the front, back and top in their relative dimensions. Pentax Q-S1 has external dimensions of 105 x 58 x 34 mm (4.13 x 2.28 x 1.34″) and weighs 203 g (0.45 lb / 7.16 oz) (including batteries). Panasonic GM1 has external dimensions of 99 x 55 x 30 mm (3.88 x 2.16 x 1.2″) and weighs 204 g (0.45 lb / 7.20 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax Q-S1 and the Panasonic GM1. Panasonic GM1 is clearly the smaller of the two cameras. Its body is 6mm narrower, 3mm shorter and 4mm thinner than Pentax Q-S1.
Here is the back view size comparison of the Pentax Q-S1 and Panasonic GM1.
Now lets look at the top view comparison of Pentax Q-S1 and Panasonic GM1.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax Q-S1 is 1g lighter than the Panasonic GM1 but we don't think this will make a significant difference.
Also keep in mind that body weight is not the only deciding factor when comparing two interchangeable camera bodies, you also have to take into account the lenses that you will be using with these bodies.
Weather Sealing
Unfortunately neither the Pentax Q-S1 nor Panasonic Lumix DMC-GM1 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 Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Pentax Q-S1 and Panasonic GM1'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.