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 Panasonic FS12 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). Panasonic FS12 has external dimensions of 97 x 55 x 22 mm (3.82 x 2.17 x 0.87″) and weighs 129 g (0.28 lb / 4.55 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon D4 and the Panasonic FS12. Panasonic FS12 is clearly the smaller of the two cameras. Its body is 63mm narrower, 102mm shorter and 69mm thinner than Nikon D4. As you can tell, actually this is not a fair size comparison since Panasonic FS12 has a built-in lens but Nikon D4 doesn't. Once you put a lens on D4, its thickness will increase significantly.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Panasonic FS12 is significantly lighter (1211g ) 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
With its weather-sealed body, we believe that the D4 has a big advantage over the FS12 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Nikon D4's 3.20" LCD screen is slightly larger than Panasonic FS12's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.