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 Fujifilm S9800 and Pentax K-S1 side-by-side from the front, back and top in their relative dimensions. Fujifilm S9800 has external dimensions of 123 x 87 x 116 mm (4.84 x 3.43 x 4.57″) and weighs 670 g (1.48 lb / 23.63 oz) (including batteries). Pentax K-S1 has external dimensions of 121 x 93 x 70 mm (4.76 x 3.66 x 2.76″) and weighs 558 g (1.23 lb / 19.68 oz) (including batteries).
Below you can see the front-view size comparison of the Fujifilm S9800 and the Pentax K-S1. Pentax K-S1 is 2mm narrower and 46mm thinner than Fujifilm S9800 but it is also 6mm taller. As you can tell, actually this is not a fair size comparison since Fujifilm S9800 has a built-in lens but Pentax K-S1 doesn't. Once you put a lens on K-S1, its thickness will increase significantly.
Here is the back view size comparison of the Fujifilm S9800 and Pentax K-S1.
Now lets look at the top view comparison of Fujifilm S9800 and Pentax K-S1.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax K-S1 is significantly lighter (112g ) than the Fujifilm S9800 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 K-S1, the total kit will weigh much higher.
Unfortunately neither the Fujifilm S9800 nor Pentax K-S1 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 Bridge Cameras with Weather Sealing Top DSLR Cameras with Weather Sealing
LCD Screen Size and Features
Fujifilm S9800 and Pentax K-S1'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.