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 FX48 and Panasonic S1 side-by-side from the front, back and top in their relative dimensions. Panasonic FX48 has external dimensions of 95 x 53 x 22 mm (3.74 x 2.09 x 0.87″) and weighs 150 g (0.33 lb / 5.29 oz) (including batteries). Panasonic S1 has external dimensions of 99 x 59 x 21 mm (3.9 x 2.32 x 0.83″) and weighs 117 g (0.26 lb / 4.13 oz) (including batteries).
Below you can see the front view size comparison of Panasonic FX48 and Panasonic S1. Panasonic FX48 is 4mm narrower and 6mm shorter than Panasonic S1 but it is also 1mm thicker.
Comparison image of Panasonic FX48 and Panasonic S1 Size, Weight and External Dimensions - Front View
Here is the back view size comparison of Panasonic FX48 and Panasonic S1.
Comparison image of Panasonic FX48 and Panasonic S1 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.
Panasonic S1 is significantly lighter (33g ) than the Panasonic FX48 which may become a big advantage especially on long walking trips.
Weather Sealing
Unfortunately neither Panasonic Lumix DMC-FX48 (Lumix DMC-FX40) nor Panasonic Lumix DMC-S1 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
Panasonic S1's 2.7" LCD screen is slightly larger than Panasonic FX48's 2.5" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.