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 Pentax X90 and Panasonic ZS8 side-by-side from the front, back and top in their relative dimensions. Pentax X90 has external dimensions of 111 x 85 x 110 mm (4.37 x 3.35 x 4.33″) and weighs 428 g (0.94 lb / 15.10 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 Pentax X90 and the Panasonic ZS8. Panasonic ZS8 is clearly the smaller of the two cameras. Its body is 6mm narrower, 27mm shorter and 77mm thinner than Pentax X90.
Here is the back view size comparison of the Pentax X90 and Panasonic ZS8.
Now lets look at the top view comparison of Pentax X90 and Panasonic ZS8.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Panasonic ZS8 is significantly lighter (218g ) than the Pentax X90 which may become a big advantage especially on long walking trips.
Weather Sealing
Unfortunately neither the Pentax X90 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 Bridge Cameras with Weather Sealing Top Compact Cameras with Weather Sealing
LCD Screen Size and Features
Panasonic ZS8's 3.00" LCD screen is slightly larger than Pentax X90's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.