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 Sony TX9 and Panasonic ZS8 side-by-side from the front, back and top in their relative dimensions. Sony TX9 has external dimensions of 98 x 60 x 18 mm (3.86 x 2.36 x 0.71″) and weighs 149 g (0.33 lb / 5.26 oz) (including batteries). Panasonic ZS8 has external dimensions of 105 x 58 x 33 mm (4.13 x 2.28 x 1.3″) and weighs 210 g (0.46 lb / 7.41 oz) (including batteries).
Below you can see the front-view size comparison of the Sony TX9 and the Panasonic ZS8. Sony TX9 is 7mm narrower and 15mm thinner than Panasonic ZS8 but it is also 2mm taller.
Here is the back view size comparison of the Sony TX9 and Panasonic ZS8.
Now lets look at the top view comparison of Sony TX9 and Panasonic ZS8.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Sony TX9 is significantly lighter (61g ) than the Panasonic ZS8 which may become a big advantage especially on long walking trips.
Weather Sealing
Unfortunately neither the Sony Cyber-shot DSC-TX9 nor Panasonic Lumix DMC-ZS8 (Lumix DMC-TZ18) 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
Sony TX9's 3.50" LCD screen is slightly larger than Panasonic ZS8's 3" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.