Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate YI M1 and Canon M3 side-by-side from the front, back and top in their relative dimensions. YI M1 has external dimensions of 114 x 64 x 34 mm (4.49 x 2.52 x 1.34″) and weighs 350 (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 YI M1 and Canon M3. YI M1 is 4mm shorter and 10mm thinner than Canon M3 but it is also 3mm wider.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
YI M1 is 16g lighter than the Canon M3 but we don't think this will make a significant difference.
Also keep in mind that body weight is not the only deciding factor when comparing two interchangeable camera bodies, you have to also take into account the lenses that you will be using with these bodies. Since Canon M3 has an APS-C sized sensor and YI M1 has a smaller Four Thirds sensor, YI M1's lenses for a similar focal length and aperture will generally be lighter and smaller than the Canon M3 lenses.
Unfortunately neither YI M1 nor Canon EOS M3 provides any type of weather sealing in their body, 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 Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
YI M1 and Canon M3's LCD screens has the same diagonal size of 3".
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 YI M1 has a fixed type screen which provides less flexibility in shooting positions compared to M3.