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 Panasonic LX100 and Panasonic ZS3 side-by-side from the front, back and top in their relative dimensions. Panasonic LX100 has external dimensions of 115 x 66 x 55 mm (4.53 x 2.6 x 2.17″) and weighs 393 g (0.87 lb / 13.86 oz) (including batteries). 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).
Below you can see the front-view size comparison of the Panasonic LX100 and the Panasonic ZS3. Panasonic ZS3 is clearly the smaller of the two cameras. Its body is 12mm narrower, 6mm shorter and 22mm thinner than Panasonic LX100.
Here is the back view size comparison of the Panasonic LX100 and Panasonic ZS3.
Now lets look at the top view comparison of Panasonic LX100 and Panasonic ZS3.
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 (164g ) than the Panasonic LX100 which may become a big advantage especially on long walking trips.
Weather Sealing
Unfortunately neither the Panasonic Lumix DMC-LX100 nor Panasonic Lumix DMC-ZS3 (Lumix DMC-TZ7) 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
Panasonic LX100 and Panasonic ZS3'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.