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 Nikon D780 and Sony A65 side-by-side from the front, back and top in their relative dimensions. 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). Sony A65 has external dimensions of 132 x 97 x 81 mm (5.2 x 3.82 x 3.19″) and weighs 622 g (1.37 lb / 21.94 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon D780 and the Sony A65. Sony A65 is 12mm narrower and 19mm shorter than Nikon D780 but it is also 5mm thicker.
Here is the back view size comparison of the Nikon D780 and Sony A65.
Now lets look at the top view comparison of Nikon D780 and Sony A65.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Sony A65 is significantly lighter (218g ) 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 Sony A65 has a smaller APS-C sensor, Sony A65's lenses for a similar focal length and aperture will generally be lighter and smaller than the Nikon D780 lenses.
Weather Sealing
With its weather-sealed body, we believe that the D780 has a big advantage over the A65 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Nikon D780's 3.20" LCD screen is slightly larger than Sony A65's 3" screen.