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 SL3 and Sony A58 side-by-side from the front, back and top in their relative dimensions. Canon SL3 has external dimensions of 122 x 93 x 70 mm (4.8 x 3.66 x 2.76″) and weighs 449 g (0.99 lb / 15.84 oz) (including batteries). Sony A58 has external dimensions of 129 x 95 x 78 mm (5.08 x 3.74 x 3.07″) and weighs 492 g (1.08 lb / 17.35 oz) (including batteries).
Below you can see the front-view size comparison of the Canon SL3 and the Sony A58. Canon SL3 is clearly the smaller of the two cameras. Its body is 7mm narrower, 2mm shorter and 8mm thinner than Sony A58.
Here is the back view size comparison of the Canon SL3 and Sony A58.
Now lets look at the top view comparison of Canon SL3 and Sony A58.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon SL3 is 43g lighter than the Sony A58 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 also have to take into account the lenses that you will be using with these bodies. Since both Canon SL3 and Sony A58 have the same APS-C sized sensor, their lenses for a similar focal length and aperture will be similar in size and weight.
Weather Sealing
Unfortunately neither the Canon EOS Rebel SL3 (EOS 250D / EOS Kiss X10) nor Sony SLT-A58 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 DSLR Cameras with Weather Sealing
LCD Screen Size and Features
Canon SL3's 3.00" LCD screen is slightly larger than Sony A58's 2.7" screen.