Sigma SD15 weighs 750 g (1.65 lb / 26.46 oz) and has external dimensions of 144 x 107 x 81 mm (5.67 x 4.21 x 3.19″). Considering that the average weight of DSLR type cameras is 774g, its weight is about average in its class. With a thickness of 81mm, it also has an average thickness.
Weight Comparison
DSLR Cameras
Thickness Comparison
DSLR Cameras
Here is the front and top view image of Sigma SD15 with the dimensions:
Front and Top View External Dimensions and Size of Sigma SD15 Camera Body
In order to give you a better idea about the real life size of Sigma SD15, we have added an image of how it looks next to a credit card and an AA type battery.
Physical size of the Sigma SD15 Body Compared to a Credit Card and an AA Battery
Now lets compare the weight and thickness of Sigma SD15 with its main competitors:
Sigma SD15 Size Compared to Main Competitors
Weather Sealing
Sigma SD15 doesn't have any environmental sealings on its body so you got to be extra careful to protect it against water and dust. If you shoot under these conditions very often, consider checking Top DSLR Cameras with Weather Sealing page.