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 Canon 1D X III and Sony RX100 VI side-by-side from the front, back and top in their relative dimensions. Canon 1D X III has external dimensions of 158 x 168 x 83 mm (6.22 x 6.61 x 3.27″) and weighs 1440 g (3.17 lb / 50.79 oz) (including batteries). Sony RX100 VI has external dimensions of 102 x 58 x 43 mm (4.02 x 2.28 x 1.69″) and weighs 301 g (0.66 lb / 10.62 oz) (including batteries).
Below you can see the front-view size comparison of the Canon 1D X III and the Sony RX100 VI. Sony RX100 VI is clearly the smaller of the two cameras. Its body is 56mm narrower, 110mm shorter and 40mm thinner than Canon 1D X III. As you can tell, actually this is not a fair size comparison since Sony RX100 VI has a built-in lens but Canon 1D X III doesn't. Once you put a lens on 1D X MIII, its thickness will increase significantly.
Here is the back view size comparison of the Canon 1D X III and Sony RX100 VI.
Now lets look at the top view comparison of Canon 1D X III and Sony RX100 VI.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Sony RX100 VI is significantly lighter (1139g ) than the Canon 1D X III 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 1D X MIII, the total kit will weigh much higher.
Weather Sealing
With its weather-sealed body, we believe that the 1D X MIII has a big advantage over the RX100 VI which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Canon 1D X III's 3.20" LCD screen is slightly larger than Sony RX100 VI's 3 screen.