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 D4 and Canon D10 side-by-side from the front, back and top in their relative dimensions. Nikon D4 has external dimensions of 160 x 157 x 91 mm (6.3 x 6.18 x 3.58″) and weighs 1340 g (2.95 lb / 47.27 oz) (including batteries). Canon D10 has external dimensions of 104 x 67 x 49 mm (4.09 x 2.64 x 1.93″) and weighs 190 g (0.42 lb / 6.70 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon D4 and the Canon D10. Canon D10 is clearly the smaller of the two cameras. Its body is 56mm narrower, 90mm shorter and 42mm thinner than Nikon D4. As you can tell, actually this is not a fair size comparison since Canon D10 has a built-in lens but Nikon D4 doesn't. Once you put a lens on D4, its thickness will increase significantly.
Here is the back view size comparison of the Nikon D4 and Canon D10.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon D10 is significantly lighter (1150g ) than the Nikon D4 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on D4, the total kit will weigh much higher.
Weather Sealing
Both the D4 and the D10 have weather sealings in their bodies, making them resistant to water and dust.
LCD Screen Size and Features
Nikon D4's 3.20" LCD screen is slightly larger than Canon D10's 2.5" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.