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 Pentax ist DS2 and Pentax K10D side-by-side from the front, back and top in their relative dimensions. Pentax ist DS2 has external dimensions of 125 x 93 x 66 mm (4.92 x 3.66 x 2.6″) and weighs 605 g (1.33 lb / 21.34 oz) (including batteries). Pentax K10D has external dimensions of 142 x 101 x 70 mm (5.59 x 3.98 x 2.76″) and weighs 793 g (1.75 lb / 27.97 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax ist DS2 and the Pentax K10D. Pentax ist DS2 is clearly the smaller of the two cameras. Its body is 17mm narrower, 8mm shorter and 4mm thinner than Pentax K10D.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax ist DS2 is significantly lighter (188g ) than the Pentax K10D 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 both Pentax ist DS2 and Pentax K10D have the same Pentax KAF lens mount and APS-C sized sensors, lenses will not be a differentiator on total size of the system.
Weather Sealing
Thanks to the weather-sealed body of the K10D, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the ist DS2.
LCD Screen Size and Features
Pentax K10D's 2.50" LCD screen is slightly larger than Pentax ist DS2's 2.5" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.