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 Nikon S9900 and Pentax Q-S1 side-by-side from the front, back and top in their relative dimensions. Nikon S9900 has external dimensions of 112 x 66 x 40 mm (4.41 x 2.6 x 1.57″) and weighs 289 g (0.64 lb / 10.19 oz) (including batteries). 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).
Below you can see the front-view size comparison of the Nikon S9900 and the Pentax Q-S1. Pentax Q-S1 is clearly the smaller of the two cameras. Its body is 7mm narrower, 8mm shorter and 6mm thinner than Nikon S9900. As you can tell, actually this is not a fair size comparison since Nikon S9900 has a built-in lens but Pentax Q-S1 doesn't. Once you put a lens on Q-S1, its thickness will increase significantly.
Here is the back view size comparison of the Nikon S9900 and Pentax Q-S1.
Now lets look at the top view comparison of Nikon S9900 and Pentax Q-S1.
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 (86g ) than the Nikon S9900 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-S1, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Nikon Coolpix S9900 nor Pentax Q-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 Compact Cameras with Weather Sealing Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Nikon S9900 and Pentax Q-S1's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Nikon S9900 sports a
Fully Articulated screen which you can change the angle and position of the screen almost freely, making it possible to shoot from waist or over-the-head levels, and especially very useful for shooting selfies and video. Pentax Q-S1's LCD screen is a fixed type which provides almost no flexibility in shooting positions compared to S9900.