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 S6100 and Panasonic ZS15 side-by-side from the front, back and top in their relative dimensions. Nikon S6100 has external dimensions of 98 x 58 x 27 mm (3.86 x 2.28 x 1.06″) and weighs 175 g (0.39 lb / 6.17 oz) (including batteries). Panasonic ZS15 has external dimensions of 105 x 58 x 33 mm (4.13 x 2.28 x 1.3″) and weighs 208 g (0.46 lb / 7.34 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon S6100 and the Panasonic ZS15. Nikon S6100 is 7mm narrower and 6mm thinner than Nikon S6100 but they have the same height of 58mm.
Here is the back view size comparison of the Nikon S6100 and Panasonic ZS15.
Now lets look at the top view comparison of Nikon S6100 and Panasonic ZS15.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Nikon S6100 is significantly lighter (33g ) than the Panasonic ZS15 which may become a big advantage especially on long walking trips.
Weather Sealing
Unfortunately neither the Nikon Coolpix S6100 nor Panasonic Lumix DMC-ZS15 (Lumix DMC-TZ25) 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
LCD Screen Size and Features
Nikon S6100 and Panasonic ZS15'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.