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 HZ25W and Nikon D90 side-by-side from the front, back and top in their relative dimensions. Samsung HZ25W has external dimensions of 116 x 83 x 92 mm (4.57 x 3.27 x 3.62″) and weighs 428 g (0.94 lb / 15.10 oz) (including batteries). Nikon D90 has external dimensions of 132 x 103 x 77 mm (5.2 x 4.06 x 3.03″) and weighs 703 g (1.55 lb / 24.80 oz) (including batteries).
Below you can see the front-view size comparison of the Samsung HZ25W and the Nikon D90. Samsung HZ25W is 16mm narrower and 20mm shorter than Nikon D90 but it is also 15mm thicker. As you can tell, actually this is not a fair size comparison since Samsung HZ25W has a built-in lens but Nikon D90 doesn't. Once you put a lens on D90, its thickness will increase significantly.
Here is the back view size comparison of the Samsung HZ25W and Nikon D90.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Samsung HZ25W is significantly lighter (275g ) than the Nikon D90 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 D90, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Samsung HZ25W (WB5000) nor Nikon D90 provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing Top DSLR Cameras with Weather Sealing
LCD Screen Size and Features
Samsung HZ25W and Nikon D90's LCD screens have the same diagonal size of 3.00 inches.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.