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 Pentax Q and Canon SX30 IS side-by-side from the front, back and top in their relative dimensions. Pentax Q has external dimensions of 98 x 57 x 31 mm (3.86 x 2.24 x 1.22″) and weighs 180 g (0.40 lb / 6.35 oz) (including batteries). Canon SX30 IS has external dimensions of 123 x 92 x 108 mm (4.84 x 3.62 x 4.25″) and weighs 601 g (1.32 lb / 21.20 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax Q and the Canon SX30 IS. Pentax Q is clearly the smaller of the two cameras. Its body is 25mm narrower, 35mm shorter and 77mm thinner than Canon SX30 IS. As you can tell, actually this is not a fair size comparison since Canon SX30 IS has a built-in lens but Pentax Q doesn't. Once you put a lens on Q, 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.
Pentax Q is significantly lighter (421g ) than the Canon SX30 IS 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 Q, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Pentax Q nor Canon PowerShot SX30 IS provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Mirrorless Cameras with Weather Sealing Top Bridge Cameras with Weather Sealing
LCD Screen Size and Features
Pentax Q's 3.00" LCD screen is slightly larger than Canon SX30 IS's 2.7" screen.