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 Sony A100 and Ricoh WG-20 side-by-side from the front, back and top in their relative dimensions. Sony A100 has external dimensions of 133 x 95 x 71 mm (5.24 x 3.74 x 2.8″) and weighs 638 g (1.41 lb / 22.50 oz) (including batteries). Ricoh WG-20 has external dimensions of 114 x 58 x 28 mm (4.49 x 2.28 x 1.1″) and weighs 164 g (0.36 lb / 5.78 oz) (including batteries).
Below you can see the front view size comparison of Sony A100 and Ricoh WG-20. Ricoh WG-20 is clearly the smaller of the two cameras. Its body is 19mm narrower, 37mm shorter and 43mm thinner than Sony A100. As you can tell, actually this is not a fair size comparison since Ricoh WG-20 has a built-in lens but Sony A100 doesn't. Once you put a lens on A100, its thickness will increase significantly.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Ricoh WG-20 is significantly lighter (474g ) than the Sony A100 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 A100, the total kit will weigh much higher.
Thanks to the weather sealed body of WG-20, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to A100.
LCD Screen Size and Features
Ricoh WG-20's 2.70" LCD screen is slightly larger than Sony A100's 2.5" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.