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 Canon A490 and Nikon D50 side-by-side from the front, back and top in their relative dimensions. Canon A490 has external dimensions of 94 x 62 x 31 mm (3.7 x 2.44 x 1.22″) and weighs 175 g (0.39 lb / 6.17 oz) (including batteries). Nikon D50 has external dimensions of 133 x 102 x 76 mm (5.24 x 4.02 x 2.99″) and weighs 620 g (1.37 lb / 21.87 oz) (including batteries).
Below you can see the front-view size comparison of the Canon A490 and the Nikon D50. Canon A490 is clearly the smaller of the two cameras. Its body is 39mm narrower, 40mm shorter and 45mm thinner than Nikon D50. As you can tell, actually this is not a fair size comparison since Canon A490 has a built-in lens but Nikon D50 doesn't. Once you put a lens on D50, 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 A490 is significantly lighter (445g ) than the Nikon D50 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 D50, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Canon PowerShot A490 nor Nikon D50 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 Top DSLR Cameras with Weather Sealing
LCD Screen Size and Features
Canon A490's 2.50" LCD screen is slightly larger than Nikon D50's 2 screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.