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 Sony TX200V and Panasonic GH4 side-by-side from the front, back and top in their relative dimensions. Sony TX200V has external dimensions of 96 x 58 x 16 mm (3.78 x 2.28 x 0.63″) and weighs 129 g (0.28 lb / 4.55 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 Sony TX200V and the Panasonic GH4. Sony TX200V is clearly the smaller of the two cameras. Its body is 37mm narrower, 35mm shorter and 68mm thinner than Panasonic GH4. As you can tell, actually this is not a fair size comparison since Sony TX200V 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 Sony TX200V and Panasonic GH4.
Now lets look at the top view comparison of Sony TX200V and Panasonic GH4.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Sony TX200V is significantly lighter (431g ) 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
Both the TX200V and the GH4 have weather sealings in their bodies, making them resistant to water and dust.
LCD Screen Size and Features
Sony TX200V's 3.30" LCD screen is slightly larger than Panasonic GH4's 3" screen.