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 Panasonic ZS1 and Nikon S9100 side-by-side from the front, back and top in their relative dimensions. Panasonic ZS1 has external dimensions of 103 x 60 x 33 mm (4.06 x 2.36 x 1.3″) and weighs 229 g (0.50 lb / 8.08 oz) (including batteries). 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).
Below you can see the front view size comparison of Panasonic ZS1 and Nikon S9100. Panasonic ZS1 is clearly the smaller of the two cameras. Its body is 2mm narrower, 2mm shorter and 2mm thinner than Nikon S9100.
Comparison image of Panasonic ZS1 and Nikon S9100 Size, Weight and External Dimensions - Front View
Here is the back view size comparison of Panasonic ZS1 and Nikon S9100.
Comparison image of Panasonic ZS1 and Nikon S9100 Size and Weight - Back View
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon S9100 is 15g lighter than the Panasonic ZS1 but we don't think this will make a significant difference.
Weather Sealing
Unfortunately neither Panasonic Lumix DMC-ZS1 (Lumix DMC-TZ6) nor Nikon Coolpix S9100 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
LCD Screen Size and Features
Nikon S9100's 3" LCD screen is slightly larger than Panasonic ZS1's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.