Digital SLR cameras body and lenses

By: Jacob Georgeson

Digital SLR cameras are usually sold in two parts: the camera body and lenses. There are many types of lenses with different characteristics from macro to zoom, with special options like image stabilizers, special filters and more. In this article you will read about some lenses options and what you should consider when buying them.
You can and should own more than one lens. Different lenses are better at different scenes. An obvious example is the difference between a macro lens used to take shots of objects from a very short distance sometimes almost touching the camera and zoom lenses designed to take photos from a far distance. Professional photographer always carry a few lenses with them and change the lens often in order to use the right one for each photo shot. Sometimes professional photographer actually carry a few cameras with different lenses mounted on them allowing them to quickly choose the perfect lens for each shot without the need to actually switch lenses back and forth.
Some lenses also provide special features that better the photos taken. For example image stabilization also known for short as IS eliminates the effect of small camera movements as the pictures is taken. Such movements are a problem in extreme cases for example when shutter speed is low in low light scenes or when using a high zoom lens taking photos from far away. In those cases every small camera movement translates to blurry digital photos. The image stabilizer (IS) is an optical electro-mechanical mechanism. Using a gyro and a floating optical element the image stabilizer senses camera movements and moves the optical element in right direction and distance to compensate for such movements.
If you need to take photos of objects from a very short distance you should consider purchasing macro lenses. Macro lenses enable the digital camera to be positioned very close to the object sometimes almost touching the object and still sharply focus on it. Common objects that photographers experiment with when using macro lenses are insects, leaves, screws, nails, bolts and more. Another challenge with macro photography is lighting. If you need to use a flash any normal flash would emit light that is too intense just because the object is closer to the camera than the focus was designed for. You can either use a flash that allows setting for such a distance or place a filter on the lens.
If you plan to use really long zoom lenses you should consider lenses that support special tripod mounts. Cameras with very long lenses are heavy and their gravity center shifts out toward the lens. In order to stabilize a camera with such lenses a special tripod attached to the lens is needed. When buying such lenses it is recommended to make sure that such a tripod can be used with the lens and if you already own a tripod that the mounting mechanism is compatible with the lens.
When buying lenses you should also take into consideration their planned usage. Tow lenses can have the same optical characteristics but for example very different weights just because they are made from different materials. If you plan to travel and carry the lens weight is important even at the cost of a higher lens price.

Taken from http://www.articlecat.com