Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Nikon L31 and Nikon P90 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 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 Nikon L31 and Nikon P90. Nikon L31 is 55mm shorter and 70mm thinner than Nikon P90 but it is also 13mm wider.
Here is the back view size comparison of Nikon L31 and Nikon P90.
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 (240g ) than the Nikon P90 which may become a big advantage especially on long walking trips.
Unfortunately neither Nikon Coolpix L31 nor Nikon Coolpix P90 provides any type of weather sealing in their body, 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 Bridge Cameras with Weather Sealing
LCD Screen Size and Features
Nikon P90's 3" LCD screen is slightly larger than Nikon L31's 2.7" 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, Nikon L31 has a fixed type screen which provides less flexibility in shooting positions compared to P90.