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 Panasonic FH20 and Nikon 1 S1 side-by-side from the front, back and top in their relative dimensions. Panasonic FH20 has external dimensions of 100 x 56 x 28 mm (3.94 x 2.2 x 1.1″) and weighs 178 g (0.39 lb / 6.28 oz) (including batteries). Nikon 1 S1 has external dimensions of 102 x 61 x 30 mm (4.02 x 2.4 x 1.18″) and weighs 197 g (0.43 lb / 6.95 oz) (including batteries).
Below you can see the front-view size comparison of the Panasonic FH20 and the Nikon 1 S1. Panasonic FH20 is clearly the smaller of the two cameras. Its body is 2mm narrower, 5mm shorter and 2mm thinner than Nikon 1 S1. As you can tell, actually this is not a fair size comparison since Panasonic FH20 has a built-in lens but Nikon 1 S1 doesn't. Once you put a lens on 1 S1, its thickness will increase significantly.
Here is the back view size comparison of the Panasonic FH20 and Nikon 1 S1.
Now lets look at the top view comparison of Panasonic FH20 and Nikon 1 S1.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Panasonic FH20 is 19g lighter than the Nikon 1 S1 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 1 S1, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Panasonic Lumix DMC-FH20 (Lumix DMC-FS30) nor Nikon 1 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 1 S1's 3.00" LCD screen is slightly larger than Panasonic FH20's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.