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 S1100pj 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 S1100pj has external dimensions of 101 x 68 x 24 mm (3.98 x 2.68 x 0.94″) and weighs 180 g (0.40 lb / 6.35 oz) (including batteries).
Below you can see the front view size comparison of Panasonic ZS1 and Nikon S1100pj. Nikon S1100pj is 2mm narrower and 9mm thinner than Panasonic ZS1 but it is also 8mm taller.
Here is the back view size comparison of Panasonic ZS1 and Nikon S1100pj.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon S1100pj is significantly lighter (49g ) than the Panasonic ZS1 which may become a big advantage especially on long walking trips.
Unfortunately neither Panasonic Lumix DMC-ZS1 (Lumix DMC-TZ6) nor Nikon Coolpix S1100pj 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 S1100pj'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.