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 Pentax K-50 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). Pentax K-50 has external dimensions of 130 x 97 x 71 mm (5.12 x 3.82 x 2.8″) and weighs 650 g (1.43 lb / 22.93 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax Q-S1 and the Pentax K-50. Pentax Q-S1 is clearly the smaller of the two cameras. Its body is 25mm narrower, 39mm shorter and 37mm thinner than Pentax K-50.
Here is the back view size comparison of the Pentax Q-S1 and Pentax K-50.
Now lets look at the top view comparison of Pentax Q-S1 and Pentax K-50.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax Q-S1 is significantly lighter (447g ) than the Pentax K-50 which may become a big advantage especially on long walking trips.
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. Since Pentax K-50 has an APS-C sized sensor and Pentax Q-S1 has a smaller 1/1.7" sensor, Pentax Q-S1's lenses for a similar focal length and aperture will generally be lighter and smaller than the Pentax K-50 lenses.
Weather Sealing
Thanks to the weather-sealed body of the K-50, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the Q-S1.
LCD Screen Size and Features
Pentax Q-S1 and Pentax K-50'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.