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 Casio EX-Z450 and Pentax E90 side-by-side from the front, back and top in their relative dimensions. Casio EX-Z450 has external dimensions of 81 x 56 x 21 mm (3.19 x 2.2 x 0.83″) and weighs 128 g (0.28 lb / 4.52 oz) (including batteries). Pentax E90 has external dimensions of 102 x 59 x 25 mm (4.02 x 2.32 x 0.98″) and weighs 145 g (0.32 lb / 5.11 oz) (including batteries).
Below you can see the front view size comparison of Casio EX-Z450 and Pentax E90. Casio EX-Z450 is clearly the smaller of the two cameras. Its body is 21mm narrower, 3mm shorter and 4mm thinner than Pentax E90.
Here is the back view size comparison of Casio EX-Z450 and Pentax E90.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Casio EX-Z450 is 17g lighter than the Pentax E90 but we don't think this will make a significant difference.
Unfortunately neither Casio Exilim EX-Z450 nor Pentax Optio E90 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
Casio EX-Z450's 3" LCD screen is slightly larger than Pentax E90's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.