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 SX720 HS and Canon M3 side-by-side from the front, back and top in their relative dimensions. Canon SX720 HS has external dimensions of 110 x 64 x 36 mm (4.33 x 2.52 x 1.42″) and weighs 270 g (0.60 lb / 9.52 oz) (including batteries). Canon M3 has external dimensions of 111 x 68 x 44 mm (4.37 x 2.68 x 1.73″) and weighs 366 g (0.81 lb / 12.91 oz) (including batteries).
Below you can see the front-view size comparison of the Canon SX720 HS and the Canon M3. Canon SX720 HS is clearly the smaller of the two cameras. Its body is 1mm narrower, 4mm shorter and 8mm thinner than Canon M3. As you can tell, actually this is not a fair size comparison since Canon SX720 HS has a built-in lens but Canon M3 doesn't. Once you put a lens on M3, its thickness will increase significantly.
Here is the back view size comparison of the Canon SX720 HS and Canon M3.
Now lets look at the top view comparison of Canon SX720 HS and Canon M3.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon SX720 HS is significantly lighter (96g ) than the Canon M3 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 M3, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Canon PowerShot SX720 HS nor Canon EOS M3 provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Canon SX720 HS and Canon M3's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Canon M3 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 SX720 HS has a fixed type screen which provides less flexibility in shooting positions compared to M3.