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 Casio EX-H20G 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). Casio EX-H20G has external dimensions of 103 x 68 x 29 mm (4.06 x 2.68 x 1.14″) and weighs 216 g (0.48 lb / 7.62 oz) (including batteries).
Below you can see the front view size comparison of Panasonic ZS3 and Casio EX-H20G.
Comparison image of Panasonic ZS3 and Casio EX-H20G Size, Weight and External Dimensions - Front View
Here is the back view size comparison of Panasonic ZS3 and Casio EX-H20G.
Comparison image of Panasonic ZS3 and Casio EX-H20G 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.
Casio EX-H20G is 13g lighter than the Panasonic ZS3 but we don't think this will make a significant difference.
Weather Sealing
Unfortunately neither Panasonic Lumix DMC-ZS3 (Lumix DMC-TZ7) nor Casio Exilim EX-H20G 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 ZS3 and Casio EX-H20G'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.