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 L31 and Nikon D300S side-by-side from the front, back and top in their relative dimensions. Nikon L31 has external dimensions of 96 x 59 x 29 mm (3.78 x 2.32 x 1.14″) and weighs 160 g (0.35 lb / 5.64 oz) (including batteries). Nikon D300S has external dimensions of 147 x 114 x 74 mm (5.79 x 4.49 x 2.91″) and weighs 938 g (2.07 lb / 33.09 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon L31 and the Nikon D300S. Nikon L31 is clearly the smaller of the two cameras. Its body is 51mm narrower, 55mm shorter and 45mm thinner than Nikon D300S. As you can tell, actually this is not a fair size comparison since Nikon L31 has a built-in lens but Nikon D300S doesn't. Once you put a lens on D300S, its thickness will increase significantly.
Here is the back view size comparison of the Nikon L31 and Nikon D300S.
Now lets look at the top view comparison of Nikon L31 and Nikon D300S.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Nikon L31 is significantly lighter (778g ) than the Nikon D300S 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 D300S, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the D300S, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the L31.
LCD Screen Size and Features
Nikon D300S's 3.00" LCD screen is slightly larger than Nikon L31's 2.7 screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.