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 T6i and Nikon D780 side-by-side from the front, back and top in their relative dimensions. Canon T6i has external dimensions of 132 x 101 x 78 mm (5.2 x 3.98 x 3.07″) and weighs 555 g (1.22 lb / 19.58 oz) (including batteries). Nikon D780 has external dimensions of 144 x 116 x 76 mm (5.67 x 4.57 x 2.99″) and weighs 840 g (1.85 lb / 29.63 oz) (including batteries).
Below you can see the front-view size comparison of the Canon T6i and the Nikon D780. Canon T6i is 12mm narrower and 15mm shorter than Nikon D780 but it is also 2mm thicker.
Comparison image of the Canon T6i and the Nikon D780 Size, Weight and External Dimensions - Front View
Here is the back view size comparison of the Canon T6i and Nikon D780.
Comparison image of the Canon T6i and the Nikon D780 Size and Weight - Back View
Now lets look at the top view comparison of Canon T6i and Nikon D780.
Top View Comparison image of the Canon T6i and the the Nikon D780 Size
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon T6i is significantly lighter (285g ) than the Nikon D780 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 Nikon D780 has a Full frame sensor and Canon T6i has a smaller APS-C sensor, Canon T6i's lenses for a similar focal length and aperture will generally be lighter and smaller than the Nikon D780 lenses.
Weather Sealing
Thanks to the weather-sealed body of the D780, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the T6i.
LCD Screen Size and Features
Nikon D780's 3.20" LCD screen is slightly larger than Canon T6i's 3 screen.