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 Canon SX40 HS 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). Canon SX40 HS has external dimensions of 123 x 92 x 108 mm (4.84 x 3.62 x 4.25″) and weighs 600 g (1.32 lb / 21.16 oz) (including batteries).
Below you can see the front view size comparison of Panasonic ZS3 and Canon SX40 HS. Panasonic ZS3 is clearly the smaller of the two cameras. Its body is 20mm narrower, 32mm shorter and 75mm thinner than Canon SX40 HS.
Here is the back view size comparison of Panasonic ZS3 and Canon SX40 HS.
Now lets look at the top view comparison of Panasonic ZS3 and Canon SX40 HS.
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 (371g ) than the Canon SX40 HS which may become a big advantage especially on long walking trips.
Unfortunately neither Panasonic Lumix DMC-ZS3 (Lumix DMC-TZ7) nor Canon PowerShot SX40 HS 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's 3" LCD screen is slightly larger than Canon SX40 HS's 2.7" screen.
On the other hand, Canon SX40 HS sports a Fully Articulated screen
which you can change the angle and position of the screen almost freely, making it possible to shoot from waist or over the head levels, and especially very useful for shooting selfies and video. On the other hand, Panasonic ZS3 has a fixed type screen which provides almost no flexibility in shooting positions compared to SX40 HS.