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 K10D and Nikon P90 side-by-side from the front, back and top in their relative dimensions. 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). Nikon P90 has external dimensions of 83 x 114 x 99 mm (3.27 x 4.49 x 3.9″) and weighs 400 g (0.88 lb / 14.11 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax K10D and the Nikon P90. Pentax K10D is 13mm shorter and 29mm thinner than Nikon P90 but it is also 59mm wider. As you can tell, actually this is not a fair size comparison since Nikon P90 has a built-in lens but Pentax K10D doesn't. Once you put a lens on K10D, its thickness will increase significantly.
Here is the back view size comparison of the Pentax K10D and Nikon P90.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Nikon P90 is significantly lighter (393g ) than the Pentax K10D 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 K10D, the total kit will weigh much higher.
Weather Sealing
With its weather-sealed body, we believe that the K10D has a big advantage over the P90 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Nikon P90's 3.00" LCD screen is slightly larger than Pentax K10D's 2.5" screen.
In addition to the size advantage, Nikon P90 LCD screen also has a
Tilting feature where you can change the angle of the screen to make it easier to shoot from waist or over-the-head levels. On the other hand, Pentax K10D has a fixed type screen which provides less flexibility in shooting positions compared to P90.