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 Olympus E-M1 and Canon SX40 HS side-by-side from the front, back and top in their relative dimensions. Olympus E-M1 has external dimensions of 130 x 94 x 63 mm (5.13 x 3.68 x 2.48″) and weighs 497 g (1.10 lb / 17.53 oz) (including batteries). Canon SX40 HS has external dimensions of 123 x 92 x 108 mm (4.84 x 3.62 x 4.25″) and weighs 600 g (1.32 lb / 21.16 oz) (including batteries).
Below you can see the front-view size comparison of the Olympus E-M1 and the Canon SX40 HS. Canon SX40 HS is 7mm narrower and 2mm shorter than Olympus E-M1 but it is also 45mm thicker. As you can tell, actually this is not a fair size comparison since Canon SX40 HS has a built-in lens but Olympus E-M1 doesn't. Once you put a lens on E-M1, its thickness will increase significantly.
Here is the back view size comparison of the Olympus E-M1 and Canon SX40 HS.
Now lets look at the top view comparison of Olympus E-M1 and Canon SX40 HS.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Olympus E-M1 is significantly lighter (103g ) than the Canon SX40 HS 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 E-M1, the total kit will weigh much higher.
Weather Sealing
With its weather-sealed body, we believe that the E-M1 has a big advantage over the SX40 HS which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Olympus E-M1's 3.00" LCD screen is slightly larger than Canon SX40 HS's 2.7 screen.