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 Sigma SD1 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). Sigma SD1 has external dimensions of 146 x 113 x 80 mm (5.75 x 4.45 x 3.15″) and weighs (including batteries).
Below you can see the front view size comparison of Nikon L31 and Sigma SD1. Nikon L31 is clearly the smaller of the two cameras. Its body is 50mm narrower, 54mm shorter and 51mm thinner than Sigma SD1. As you can tell, actually this is not a fair size comparison since Nikon L31 has a built-in lens but Sigma SD1 doesn't. Once you put a lens on SD1, its thickness will increase significantly.
Now lets look at the top view comparison of Nikon L31 and Sigma SD1.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Sigma SD1 is 160g lighter than the Nikon L31 but we don't think this will make a significant difference.
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 SD1, the total kit will weigh much higher.
Thanks to the weather sealed body of SD1, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to L31.
LCD Screen Size and Features
Sigma SD1's 3" 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.