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 Samsung NX100 and Pentax RS1500 side-by-side from the front, back and top in their relative dimensions. Samsung NX100 has external dimensions of 120 x 71 x 35 mm (4.72 x 2.8 x 1.38″) and weighs 282 g (0.62 lb / 9.95 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 Samsung NX100 and the Pentax RS1500. Pentax RS1500 is clearly the smaller of the two cameras. Its body is 6mm narrower, 13mm shorter and 7mm thinner than Samsung NX100. As you can tell, actually this is not a fair size comparison since Pentax RS1500 has a built-in lens but Samsung NX100 doesn't. Once you put a lens on NX100, its thickness will increase significantly.
Now lets look at the top view comparison of Samsung NX100 and Pentax RS1500.
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 (125g ) than the Samsung NX100 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 NX100, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the RS1500, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the NX100.
LCD Screen Size and Features
Samsung NX100's 3.00" LCD screen is slightly larger than Pentax RS1500's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.