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 D80 and Canon SX20 IS side-by-side from the front, back and top in their relative dimensions. Nikon D80 has external dimensions of 132 x 103 x 77 mm (5.2 x 4.06 x 3.03″) and weighs 668 g (1.47 lb / 23.56 oz) (including batteries). Canon SX20 IS has external dimensions of 128 x 88 x 87 mm (5.04 x 3.46 x 3.43″) and weighs 600 g (1.32 lb / 21.16 oz) (including batteries).
Below you can see the front view size comparison of Nikon D80 and Canon SX20 IS. Canon SX20 IS is 4mm narrower and 15mm shorter than Nikon D80 but it is also 10mm thicker. As you can tell, actually this is not a fair size comparison since Canon SX20 IS has a built-in lens but Nikon D80 doesn't. Once you put a lens on D80, 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.
Canon SX20 IS is 68g lighter than the Nikon D80 but we don't think this will make a significant difference.
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 D80, the total kit will weigh much higher.
Unfortunately neither Nikon D80 nor Canon PowerShot SX20 IS 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 DSLR Cameras with Weather Sealing Top Bridge Cameras with Weather Sealing
LCD Screen Size and Features
Nikon D80 and Canon SX20 IS's LCD screens has the same diagonal size of 2.5".
On the other hand, Canon SX20 IS sports a Fully Articulated screen
which you can change the angle and position of the screen almost freely, making it possible to shoot from waist or over the head levels, and especially very useful for shooting selfies and video. Nikon D80's LCD screen is a fixed type which provides almost no flexibility in shooting positions compared to SX20 IS.