The Canon EF-S 18-200mm lens is an all purpose zoom lens.
The Canon EF-S 18-200mm lens is an all-purpose lens designed to work with Canon's digital single lens reflex cameras that use the APS-C format sensor. These sensors have 1.6 crop factor giving the 18-200mm lens a field of view equivalent to a 28.8 to 320mm lens. The zoom coverage makes this lens a one lens choice for most of the shooting requirements an amateur photographer may have. Like the rest of Canon's EF lenses, to open the lens to its maximum aperture is controlled through the camera.
Instructions
1. Hold your Canon APS-C digital single lens reflex camera in your hand and line up the red dot on the barrel of the lens and the red dot on the camera's mounting ring.
2. Place the lens against the mounting ring and rotate the lens until it clicks into place.
3. Turn your Canon camera on either by using the power switch on the back of the camera or on the top plate of the camera, depending on the model of Canon camera you are using.
4. Rotate the exposure mode dial located on the top left for the "D" cameras and on the top right for the "Rebel" cameras to the "Av" setting. This is short form for "Aperture Value" and means you now have control over the aperture setting for the camera. You can also use the "M" for "Manual" mode and have control over the aperture setting as well as the shutter speed.
5. Turn the small wheel just by the shutter release button to adjust the aperture. The maximum aperture or widest opening is f3.5 when the lens is set at its 18mm point. The aperture reduces as the focal length of the lens is adjusted. At the 200mm focal length, the maximum aperture is f5.6. When the aperture is set to its maximum opening at 18mm, the camera will automatically adjust the aperture setting to the widest as the focal length is changing. This is true in "Av" and "M" shooting mode. The camera does not do the same if you start at 200mm and f5.6. It won't automatically open the lens up as the focal length is decreased.
Tags: focal length, 18-200mm lens, aperture setting, maximum aperture, adjust aperture, aperture maximum, Canon camera