Pentax K-S1 weighs 558 g (1.23 lb / 19.68 oz) and has external dimensions of 121 x 93 x 70 mm (4.76 x 3.66 x 2.76″). Considering that the average weight of DSLR type cameras is 774g, Pentax K-S1 is a remarkably light camera for its class. With a thickness of 70mm, it has an average thickness for its class.
Here is the front and top view image of Pentax K-S1 with the dimensions:
In order to give you a better idea about the real life size of Pentax K-S1, we have added an image of how it looks next to a credit card and an AA type battery.
Now lets compare the weight and thickness of Pentax K-S1 with its main competitors:
Pentax K-S1 doesn't have any environmental sealings on its body so you got to be extra careful to protect it against water and dust. If you shoot under these conditions very often, consider checking Top DSLR Cameras with Weather Sealing page.
One of our favourite features on Pentax K-S1 is its illuminated buttons which makes it easier to find and press the right buttons under dark conditions.