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 A7 III and Canon SX420 IS side-by-side from the front, back and top in their relative dimensions. Sony A7 III has external dimensions of 127 x 96 x 74 mm (5 x 3.78 x 2.91″) and weighs 650 g (1.43 lb / 22.93 oz) (including batteries). Canon SX420 IS has external dimensions of 104 x 69 x 85 mm (4.09 x 2.72 x 3.35″) and weighs 325 g (0.72 lb / 11.46 oz) (including batteries).
Below you can see the front-view size comparison of the Sony A7 III and the Canon SX420 IS. Canon SX420 IS is 23mm narrower and 27mm shorter than Sony A7 III but it is also 11mm thicker. As you can tell, actually this is not a fair size comparison since Canon SX420 IS has a built-in lens but Sony A7 III doesn't. Once you put a lens on A7 III, its thickness will increase significantly.
Here is the back view size comparison of the Sony A7 III and Canon SX420 IS.
Now lets look at the top view comparison of Sony A7 III and Canon SX420 IS.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon SX420 IS is significantly lighter (325g ) than the Sony A7 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 A7 III, the total kit will weigh much higher.
Weather Sealing
With its weather-sealed body, we believe that the A7 III has a big advantage over the SX420 IS which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Sony A7 III and Canon SX420 IS's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Sony A7 III features a
Tilting screen where you can change the angle of the screen to make it easier to shoot from waist or over-the-head levels whereas the Canon SX420 IS has a fixed type screen which provides less flexibility in shooting positions compared to A7 III.