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 LZ30 and Panasonic LZ40 side-by-side from the front, back and top in their relative dimensions. Panasonic LZ30 has external dimensions of 124 x 84 x 92 mm (4.88 x 3.31 x 3.62″) and weighs 552 g (1.22 lb / 19.47 oz) (including batteries). Panasonic LZ40 has external dimensions of 126 x 87 x 94 mm (4.96 x 3.43 x 3.7″) and weighs 524 g (1.16 lb / 18.48 oz) (including batteries).
Below you can see the front view size comparison of Panasonic LZ30 and Panasonic LZ40. Panasonic LZ30 is clearly the smaller of the two cameras. Its body is 2mm narrower, 3mm shorter and 2mm thinner than Panasonic LZ40.
Now lets look at the top view comparison of Panasonic LZ30 and Panasonic LZ40.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Panasonic LZ40 is 28g lighter than the Panasonic LZ30 but we don't think this will make a significant difference.
Unfortunately neither Panasonic Lumix DMC-LZ30 nor Panasonic Lumix DMC-LZ40 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 Bridge Cameras with Weather Sealing
LCD Screen Size and Features
Panasonic LZ30 and Panasonic LZ40'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.