Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Nikon S9100 and Canon SX510 HS side-by-side from the front, back and top in their relative dimensions. Nikon S9100 has external dimensions of 105 x 62 x 35 mm (4.13 x 2.44 x 1.38″) and weighs 214 g (0.47 lb / 7.55 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 Nikon S9100 and Canon SX510 HS. Nikon S9100 is 8mm shorter and 45mm thinner than Canon SX510 HS but it is also 1mm wider.
Now lets look at the top view comparison of Nikon S9100 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 S9100 is significantly lighter (135g ) than the Canon SX510 HS which may become a big advantage especially on long walking trips.
Unfortunately neither Nikon Coolpix S9100 nor Canon PowerShot SX510 HS provides any type of weather sealing in their body, 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 S9100 and Canon SX510 HS's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.