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 L120 and Pentax K-30 side-by-side from the front, back and top in their relative dimensions. Nikon L120 has external dimensions of 110 x 77 x 78 mm (4.33 x 3.03 x 3.07″) and weighs 431 g (0.95 lb / 15.20 oz) (including batteries). Pentax K-30 has external dimensions of 130 x 97 x 71 mm (5.12 x 3.82 x 2.8″) and weighs 650 g (1.43 lb / 22.93 oz) (including batteries).
Below you can see the front view size comparison of Nikon L120 and Pentax K-30. Nikon L120 is 20mm narrower and 20mm shorter than Pentax K-30 but it is also 7mm thicker. As you can tell, actually this is not a fair size comparison since Nikon L120 has a built-in lens but Pentax K-30 doesn't. Once you put a lens on K-30, its thickness will increase significantly.
Comparison image of Nikon L120 and Pentax K-30 Size, Weight and External Dimensions - Front View
Now lets look at the top view comparison of Nikon L120 and Pentax K-30.
Top View Comparison image of Nikon L120 and Pentax K-30 Size
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon L120 is significantly lighter (219g ) than the Pentax K-30 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 K-30, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather sealed body of K-30, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to L120.
LCD Screen Size and Features
Nikon L120 and Pentax K-30's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.