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 GF5 and Panasonic GF3 side-by-side from the front, back and top in their relative dimensions. Panasonic GF5 has external dimensions of 108 x 67 x 37 mm (4.25 x 2.64 x 1.46″) and weighs 267 g (0.59 lb / 9.42 oz) (including batteries). Panasonic GF3 has external dimensions of 108 x 67 x 32 mm (4.25 x 2.64 x 1.26″) and weighs 264 g (0.58 lb / 9.31 oz) (including batteries).
Below you can see the front view size comparison of Panasonic GF5 and Panasonic GF3. Panasonic GF5 has the same height and width with Panasonic GF3. On the other hand, with a thickness of 37mm, it is 5mm thicker.
Now lets look at the top view comparison of Panasonic GF5 and Panasonic GF3.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Panasonic GF3 is 3g lighter than the Panasonic GF5 but we don't think this will make a significant difference.
Also keep in mind that body weight is not the only deciding factor when comparing two interchangeable camera bodies, you have to also take into account the lenses that you will be using with these bodies. Since both Panasonic GF5 and Panasonic GF3 have the same Micro Four Thirds lens mount and Four Thirds sized sensors, lenses will not be a differentiator on total size of the system.
Unfortunately neither Panasonic Lumix DMC-GF5 nor Panasonic Lumix DMC-GF3 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 Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Panasonic GF5 and Panasonic GF3's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.