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 Fujifilm X20 and Panasonic GH4 side-by-side from the front, back and top in their relative dimensions. Fujifilm X20 has external dimensions of 117 x 70 x 57 mm (4.61 x 2.76 x 2.24″) and weighs 353 g (0.78 lb / 12.45 oz) (including batteries). Panasonic GH4 has external dimensions of 133 x 93 x 84 mm (5.24 x 3.66 x 3.31″) and weighs 560 g (1.23 lb / 19.75 oz) (including batteries).
Below you can see the front-view size comparison of the Fujifilm X20 and the Panasonic GH4. Fujifilm X20 is clearly the smaller of the two cameras. Its body is 16mm narrower, 23mm shorter and 27mm thinner than Panasonic GH4. As you can tell, actually this is not a fair size comparison since Fujifilm X20 has a built-in lens but Panasonic GH4 doesn't. Once you put a lens on GH4, its thickness will increase significantly.
Here is the back view size comparison of the Fujifilm X20 and Panasonic GH4.
Now lets look at the top view comparison of Fujifilm X20 and Panasonic GH4.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Fujifilm X20 is significantly lighter (207g ) than the Panasonic GH4 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on GH4, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the GH4, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the X20.
LCD Screen Size and Features
Panasonic GH4's 3.00" LCD screen is slightly larger than Fujifilm X20's 2.8 screen.
Moreover, Panasonic GH4 sports a
Fully Articulated screen which you can change the angle and position of the screen almost freely, making it possible to shoot from waist or over-the-head levels, and especially very useful for shooting selfies and video. On the other hand, Fujifilm X20 has a fixed type screen which provides almost no flexibility in shooting positions compared to GH4.