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 1Ds MIII and Canon SL3 side-by-side from the front, back and top in their relative dimensions. Canon 1Ds MIII has external dimensions of 150 x 160 x 80 mm (5.91 x 6.3 x 3.15″) and weighs 1385 g (3.05 lb / 48.85 oz) (including batteries). 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).
Below you can see the front-view size comparison of the Canon 1Ds MIII and the Canon SL3. Canon SL3 is clearly the smaller of the two cameras. Its body is 28mm narrower, 67mm shorter and 10mm thinner than Canon 1Ds MIII.
Here is the back view size comparison of the Canon 1Ds MIII and Canon SL3.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon SL3 is significantly lighter (936g ) than the Canon 1Ds MIII 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 also have to take into account the lenses that you will be using with these bodies. Since Canon 1Ds MIII has a Full frame sensor and Canon SL3 has a smaller APS-C sensor, Canon SL3's lenses for a similar focal length and aperture will generally be lighter and smaller than the Canon 1Ds MIII lenses.
Weather Sealing
With its weather-sealed body, we believe that the 1Ds MIII has a big advantage over the SL3 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Canon 1Ds MIII and Canon SL3's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Canon SL3 sports a
Fully Articulated screen which you can change the angle and position of the screen almost freely, making it possible to shoot from waist or over-the-head levels, and especially very useful for shooting selfies and video. Canon 1Ds MIII's LCD screen is a fixed type which provides almost no flexibility in shooting positions compared to SL3.