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 Nikon P510 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). Nikon P510 has external dimensions of 120 x 83 x 102 mm (4.72 x 3.27 x 4.02″) and weighs 555 g (1.22 lb / 19.58 oz) (including batteries).
Below you can see the front-view size comparison of the Pentax Q and the Nikon P510. Pentax Q is clearly the smaller of the two cameras. Its body is 22mm narrower, 26mm shorter and 71mm thinner than Nikon P510. As you can tell, actually this is not a fair size comparison since Nikon P510 has a built-in lens but Pentax Q doesn't. Once you put a lens on Q, its thickness will increase significantly.
Here is the back view size comparison of the Pentax Q and Nikon P510.
Now lets look at the top view comparison of Pentax Q and Nikon P510.
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 (375g ) than the Nikon P510 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 Nikon Coolpix P510 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 and Nikon P510's LCD screens have the same diagonal size of 3.00 inches.
On the other hand, Nikon P510 features a
Tilting screen where you can change the angle of the screen to make it easier to shoot from waist or over-the-head levels whereas the Pentax Q has a fixed type screen which provides less flexibility in shooting positions compared to P510.