The Canon EOS Digital Rebel XSi/450D Companion

ANATOMY OF THE REBEL XSI

THE LENS

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Use a blower brush for cleaning dust off the ends of your lenses.

One of the best things you can do to ensure the long-term health of a lens is to

put a protective filter on the end. A skylight or UV filter will not alter the light

that passes through the lens but will provide a significant amount of protection.

If the filter gets scratched, you can simply replace it. Even in the event of a drop,

a filter can absorb a lot of the impact that would normally smash up the front of

the lens.

When shopping for a filter, spend a little more money and buy a multicoated filter.

Multi-coated filters have special chemicals on them that reduce flare and other

reflections and other image-damaging phenomena. If you’ve spent a lot of money

on a lens, don’t hobble it with a cheap, low-quality filter.

Sensor Cleaning

Because you can remove the lens on the XSi, the sensor chamber is exposed to

the outside world in a way that it never is on a point-and-shoot camera. is

means it’s possible for dust and other fine debris to get on the image sensor. And,

because you don’t ever remove the sensor and replace it with another one —as

you do with the film in a film camera—once there’s dust on the sensor, it’s there

to stay unless you take action.

Pixels on your sensor are very, very tiny. Remember, 12 million of them are

crammed into a space that’s smaller than a piece of 35mm film. ...