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 and Panasonic FS25 side-by-side from the front, back and top in their relative dimensions. Pentax Q has external dimensions of 98 x 57 x 31 mm (3.86 x 2.24 x 1.22″) and weighs 180 g (0.40 lb / 6.35 oz) (including batteries). Panasonic FS25 has external dimensions of 97 x 58 x 22 mm (3.82 x 2.28 x 0.87″) and weighs 148 g (0.33 lb / 5.22 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax Q and the Panasonic FS25. Panasonic FS25 is 1mm narrower and 9mm thinner than Pentax Q but it is also 1mm taller. As you can tell, actually this is not a fair size comparison since Panasonic FS25 has a built-in lens but Pentax Q doesn't. Once you put a lens on Q, its thickness will increase significantly.
Comparison image of the Pentax Q and the Panasonic FS25 Size, Weight and External Dimensions - Front View
Here is the back view size comparison of the Pentax Q and Panasonic FS25.
Comparison image of the Pentax Q and the Panasonic FS25 Size and Weight - Back View
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Panasonic FS25 is significantly lighter (32g ) than the Pentax Q 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 Q, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Pentax Q nor Panasonic Lumix DMC-FS25 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 Top Compact Cameras with Weather Sealing
LCD Screen Size and Features
Pentax Q and Panasonic FS25'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.