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 SX20 IS and Canon 1D MIV side-by-side from the front, back and top in their relative dimensions. 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). Canon 1D MIV has external dimensions of 156 x 157 x 80 mm (6.14 x 6.18 x 3.15″) and weighs 1230 g (2.71 lb / 43.39 oz) (including batteries).
Below you can see the front-view size comparison of the Canon SX20 IS and the Canon 1D MIV. Canon SX20 IS is 28mm narrower and 69mm shorter than Canon 1D MIV but it is also 7mm thicker. As you can tell, actually this is not a fair size comparison since Canon SX20 IS has a built-in lens but Canon 1D MIV doesn't. Once you put a lens on 1D MIV, 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 significantly lighter (630g ) than the Canon 1D MIV 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 1D MIV, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the 1D MIV, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the SX20 IS.
LCD Screen Size and Features
Canon 1D MIV's 3.00" LCD screen is slightly larger than Canon SX20 IS's 2.5" screen.
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. On the other hand, Canon 1D MIV has a fixed type screen which provides almost no flexibility in shooting positions compared to SX20 IS.