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 D2X and Pentax RS1500 side-by-side from the front, back and top in their relative dimensions. Nikon D2X has external dimensions of 158 x 150 x 86 mm (6.22 x 5.91 x 3.39″) and weighs 1200 g (2.65 lb / 42.33 oz) (including batteries). Pentax RS1500 has external dimensions of 114 x 58 x 28 mm (4.49 x 2.28 x 1.1″) and weighs 157 g (0.35 lb / 5.54 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon D2X and the Pentax RS1500. Pentax RS1500 is clearly the smaller of the two cameras. Its body is 44mm narrower, 92mm shorter and 58mm thinner than Nikon D2X. As you can tell, actually this is not a fair size comparison since Pentax RS1500 has a built-in lens but Nikon D2X doesn't. Once you put a lens on D2X, 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.
Pentax RS1500 is significantly lighter (1043g ) than the Nikon D2X 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 D2X, the total kit will weigh much higher.
Weather Sealing
Both the D2X and the RS1500 have weather sealings in their bodies, making them resistant to water and dust.
LCD Screen Size and Features
Pentax RS1500's 2.70" LCD screen is slightly larger than Nikon D2X's 2.5 screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.