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 Olympus FE-4030 and Canon 450D side-by-side from the front, back and top in their relative dimensions. Olympus FE-4030 has external dimensions of 93 x 56 x 22 mm (3.66 x 2.2 x 0.87″) and weighs 146 g (0.32 lb / 5.15 oz) (including batteries). Canon 450D has external dimensions of 129 x 98 x 62 mm (5.08 x 3.86 x 2.44″) and weighs 524 g (1.16 lb / 18.48 oz) (including batteries).
Below you can see the front-view size comparison of the Olympus FE-4030 and the Canon 450D. Olympus FE-4030 is clearly the smaller of the two cameras. Its body is 36mm narrower, 42mm shorter and 40mm thinner than Canon 450D. As you can tell, actually this is not a fair size comparison since Olympus FE-4030 has a built-in lens but Canon 450D doesn't. Once you put a lens on 450D, 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.
Olympus FE-4030 is significantly lighter (378g ) than the Canon 450D 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 450D, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Olympus FE-4030 nor Canon EOS 450D (EOS Rebel XSi / EOS Kiss X2) 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 450D's 3.00" LCD screen is slightly larger than Olympus FE-4030's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.