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 Sony A57 and Pentax WG-1 GPS side-by-side from the front, back and top in their relative dimensions. Sony A57 has external dimensions of 132 x 98 x 81 mm (5.2 x 3.86 x 3.19″) and weighs 618 g (1.36 lb / 21.80 oz) (including batteries). Pentax WG-1 GPS has external dimensions of 116 x 59 x 29 mm (4.55 x 2.3 x 1.12″) and weighs 167 g (0.37 lb / 5.89 oz) (including batteries).
Below you can see the front-view size comparison of the Sony A57 and the Pentax WG-1 GPS. Pentax WG-1 GPS is clearly the smaller of the two cameras. Its body is 16mm narrower, 39mm shorter and 52mm thinner than Sony A57. As you can tell, actually this is not a fair size comparison since Pentax WG-1 GPS has a built-in lens but Sony A57 doesn't. Once you put a lens on A57, its thickness will increase significantly.
Now lets look at the top view comparison of Sony A57 and Pentax WG-1 GPS.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Pentax WG-1 GPS is significantly lighter (451g ) than the Sony A57 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 A57, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the WG-1 GPS, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the A57.
LCD Screen Size and Features
Sony A57's 3.00" LCD screen is slightly larger than Pentax WG-1 GPS's 2.7" screen.
Moreover, Sony A57 sports a
Fully Articulated screen which you can change the angle and position of the screen almost freely, making it possible to shoot from waist or over-the-head levels, and especially very useful for shooting selfies and video. On the other hand, Pentax WG-1 GPS has a fixed type screen which provides almost no flexibility in shooting positions compared to A57.