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 Canon M3 and Samsung NX3000 side-by-side from the front, back and top in their relative dimensions. 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). Samsung NX3000 has external dimensions of 117 x 66 x 39 mm (4.61 x 2.6 x 1.54″) and weighs 230 g (including batteries).
Below you can see the front view size comparison of Canon M3 and Samsung NX3000. Samsung NX3000 is 2mm shorter and 5mm thinner than Canon M3 but it is also 6mm wider.
Here is the back view size comparison of Canon M3 and Samsung NX3000.
Now lets look at the top view comparison of Canon M3 and Samsung NX3000.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Samsung NX3000 is significantly lighter (136g ) than the Canon M3 which may become a big advantage especially on long walking trips.
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 both Canon M3 and Samsung NX3000 have the same APS-C sized sensor, their lenses for a similar focal length and aperture will be similar in size and weight.
Unfortunately neither Canon EOS M3 nor Samsung NX3000 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
Canon M3 and Samsung NX3000's LCD screens has the same diagonal size of 3".
Both cameras feature Tilting screens
where you can change the angle of the screen to make it easier to shoot from waist or over the head levels.