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 ZS3 and FujiFilm S4000 side-by-side from the front, back and top in their relative dimensions. Panasonic ZS3 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). FujiFilm S4000 has external dimensions of 118 x 81 x 100 mm (4.65 x 3.19 x 3.94″) and weighs 540 g (1.19 lb / 19.05 oz) (including batteries).
Below you can see the front view size comparison of Panasonic ZS3 and FujiFilm S4000. Panasonic ZS3 is clearly the smaller of the two cameras. Its body is 15mm narrower, 21mm shorter and 67mm thinner than FujiFilm S4000.
Here is the back view size comparison of Panasonic ZS3 and FujiFilm S4000.
Now lets look at the top view comparison of Panasonic ZS3 and FujiFilm S4000.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Panasonic ZS3 is significantly lighter (311g ) than the FujiFilm S4000 which may become a big advantage especially on long walking trips.
Unfortunately neither Panasonic Lumix DMC-ZS3 (Lumix DMC-TZ7) nor FujiFilm FinePix S4000 (FinePix S4050) 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 Top Bridge Cameras with Weather Sealing
LCD Screen Size and Features
Panasonic ZS3 and FujiFilm S4000's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.