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 Panasonic ZR3 and Pentax P70 side-by-side from the front, back and top in their relative dimensions. Panasonic ZR3 has external dimensions of 98 x 55 x 26 mm (3.86 x 2.17 x 1.02″) and weighs 159 g (0.35 lb / 5.61 oz) (including batteries). Pentax P70 has external dimensions of 97 x 54 x 22 mm (3.82 x 2.13 x 0.87″) and weighs 155 g (0.34 lb / 5.47 oz) (including batteries).
Below you can see the front-view size comparison of the Panasonic ZR3 and the Pentax P70. Pentax P70 is clearly the smaller of the two cameras. Its body is 1mm narrower, 1mm shorter and 4mm thinner than Panasonic ZR3.
Here is the back view size comparison of the Panasonic ZR3 and Pentax P70.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax P70 is 4g lighter than the Panasonic ZR3 but we don't think this will make a significant difference.
Weather Sealing
Unfortunately neither the Panasonic Lumix DMC-ZR3 (Lumix DMC-ZX3) nor Pentax Optio P70 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
Panasonic ZR3 and Pentax P70's LCD screens have the same diagonal size of 2.70 inches.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.