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 Nikon P300 and Canon SX510 HS side-by-side from the front, back and top in their relative dimensions. Nikon P300 has external dimensions of 103 x 58 x 32 mm (4.06 x 2.28 x 1.26″) and weighs 189 g (0.42 lb / 6.67 oz) (including batteries). Canon SX510 HS has external dimensions of 104 x 70 x 80 mm (4.09 x 2.76 x 3.15″) and weighs 349 g (0.77 lb / 12.31 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon P300 and the Canon SX510 HS. Nikon P300 is clearly the smaller of the two cameras. Its body is 1mm narrower, 12mm shorter and 48mm thinner than Canon SX510 HS.
Now lets look at the top view comparison of Nikon P300 and Canon SX510 HS.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Nikon P300 is significantly lighter (160g ) than the Canon SX510 HS which may become a big advantage especially on long walking trips.
Weather Sealing
Unfortunately neither the Nikon Coolpix P300 nor Canon PowerShot SX510 HS 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 Compact Cameras with Weather Sealing
LCD Screen Size and Features
Nikon P300 and Canon SX510 HS's LCD screens have the same diagonal size of 3.00 inches.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.