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 A1100 IS and Canon 1D MII side-by-side from the front, back and top in their relative dimensions. Canon A1100 IS has external dimensions of 95 x 62 x 31 mm (3.74 x 2.44 x 1.22″) and weighs 150 g (0.33 lb / 5.29 oz) (including batteries). Canon 1D MII has external dimensions of 156 x 158 x 80 mm (6.14 x 6.22 x 3.15″) and weighs 1565 g (3.45 lb / 55.20 oz) (including batteries).
Below you can see the front-view size comparison of the Canon A1100 IS and the Canon 1D MII. Canon A1100 IS is clearly the smaller of the two cameras. Its body is 61mm narrower, 96mm shorter and 49mm thinner than Canon 1D MII. As you can tell, actually this is not a fair size comparison since Canon A1100 IS has a built-in lens but Canon 1D MII doesn't. Once you put a lens on 1D MII, 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 A1100 IS is significantly lighter (1415g ) than the Canon 1D MII 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 MII, the total kit will weigh much higher.
Weather Sealing
Thanks to the weather-sealed body of the 1D MII, you can use this camera with more confidence under conditions where there is risk of exposure to water and dust compared to the A1100 IS.
LCD Screen Size and Features
Canon A1100 IS's 2.50" LCD screen is slightly larger than Canon 1D MII's 2 screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.