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 GH5 and Olympus E-M1 III side-by-side from the front, back and top in their relative dimensions. Panasonic GH5 has external dimensions of 139 x 98 x 87 mm (5.47 x 3.86 x 3.43″) and weighs 725 g (1.60 lb / 25.57 oz) (including batteries). Olympus E-M1 III has external dimensions of 134 x 91 x 69 mm (5.28 x 3.58 x 2.72″) and weighs 580 g (1.28 lb / 20.46 oz) (including batteries).
Below you can see the front view size comparison of Panasonic GH5 and Olympus E-M1 III. Olympus E-M1 III is clearly the smaller of the two cameras. Its body is 5mm narrower, 7mm shorter and 18mm thinner than Panasonic GH5.
Here is the back view size comparison of Panasonic GH5 and Olympus E-M1 III.
Now lets look at the top view comparison of Panasonic GH5 and Olympus E-M1 III.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Olympus E-M1 III is significantly lighter (145g ) than the Panasonic GH5 which may become a big advantage especially on long walking trips.
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 GH5 and Olympus E-M1 III 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.
Both GH5 and E-M1 III have weather sealings in their body, making them resistant to water and dust.
LCD Screen Size and Features
Panasonic GH5's 3.2 LCD screen is slightly larger than Olympus E-M1 III's 3" screen.