Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Nikon S9100 and Sony NEX-C3 side-by-side from the front, back and top in their relative dimensions. Nikon S9100 has external dimensions of 105 x 62 x 35 mm (4.13 x 2.44 x 1.38″) and weighs 214 g (0.47 lb / 7.55 oz) (including batteries). Sony NEX-C3 has external dimensions of 110 x 60 x 33 mm (4.33 x 2.36 x 1.3″) and weighs 225 g (0.50 lb / 7.94 oz) (including batteries).
Below you can see the front view size comparison of Nikon S9100 and Sony NEX-C3. Sony NEX-C3 is 2mm shorter and 2mm thinner than Nikon S9100 but it is also 5mm wider. As you can tell, actually this is not a fair size comparison since Nikon S9100 has a built-in lens but Sony NEX-C3 doesn't. Once you put a lens on NEX-C3, its thickness will increase significantly.
Here is the back view size comparison of Nikon S9100 and Sony NEX-C3.
Now lets look at the top view comparison of Nikon S9100 and Sony NEX-C3.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon S9100 is 11g lighter than the Sony NEX-C3 but we don't think this will make a significant difference.
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 NEX-C3, the total kit will weigh much higher.
Unfortunately neither Nikon Coolpix S9100 nor Sony Alpha NEX-C3 provides any type of weather sealing in their body, 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 S9100 and Sony NEX-C3's LCD screens has the same diagonal size of 3".
On the other hand, Sony NEX-C3 features a Tilting screen
where you can change the angle of the screen to make it easier to shoot from waist or over the head levels whereas the Nikon S9100 has a fixed type screen which provides less flexibility in shooting positions compared to NEX-C3.