The camera lens is a vital part of the photo capturing process because it molds and shapes the light that comes through to the sensor. On single-lens reflex cameras, the lens can be changed to help the photographer achieve the perfect shot. Some of the features to be familiar with when looking for a camera lens are aperture, focal length, focus type, size and cost.
Aperture
The aperture is how much light a camera lens is able to take in. The wider the aperture, the more light can enter, and the smaller the aperture number. When more light enters, this allows for a faster shutter speed which gives the photographer the ability to freeze action.
Focal Length
A camera lens can either have a fixed focal length or a range of focal lengths, which is referred to as a zoom lens. Focal length is measured in millimeters and the higher the number, the more a lens has zooming power. For example, between 40 and 60 mm represents the viewing range of the human eye. A telephoto lens of 200 mm can zoom in about four times as far.
Focus Type
Most cameras offer manual focus and automatic focus, meaning the photographer can set the focus or allow the camera to do it. However, some go a step further and allow the photographer to adjust the manual focus without having to change the mode on the lens. This is useful when you want to slightly alter the auto focus.
Size
Depending on the usage, a smaller, lighter lens may be more practical to buy than a larger one. Typically, the more powerful the zoom, the larger the lens. However, Canon has introduced lenses with the abbreviation DO, for "Diffractive Optic," that have significantly less length and weight.
Cost
A camera lens can cost under $100 to several thousand dollars. It is important to set a budget based on your usage to help determine how much you want to spend on a lens.
Tags: camera lens, manual focus, more light