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 T7i and Canon 1Ds MIII side-by-side from the front, back and top in their relative dimensions. Canon T7i has external dimensions of 131 x 100 x 76 mm (5.16 x 3.94 x 2.99″) and weighs 532 g (1.17 lb / 18.77 oz) (including batteries). 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).
Below you can see the front-view size comparison of the Canon T7i and the Canon 1Ds MIII. Canon T7i is clearly the smaller of the two cameras. Its body is 19mm narrower, 60mm shorter and 4mm thinner than Canon 1Ds MIII.
Here is the back view size comparison of the Canon T7i and Canon 1Ds MIII.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon T7i is significantly lighter (853g ) 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 T7i has a smaller APS-C sensor, Canon T7i's lenses for a similar focal length and aperture will generally be lighter and smaller than the Canon 1Ds MIII lenses.
Weather Sealing
Thanks to the weather-sealed body of the 1Ds MIII, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the T7i.
LCD Screen Size and Features
Canon T7i and Canon 1Ds MIII's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Canon T7i 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 T7i.