Guest Author - Kaye Barnett
If you own a camera with interchangeable lenses you'll know that there are so many other different lenses to choose from! Many of the lenses available now, inbuilt or interchangeable are zoom lenses incorporating a range of focal lengths. Which means you can zoom from one focal length to another. This article will guide you through the different lens focal length, how and when they are best used and what sort of photos they will produce. But even if you don't own a camera with an interchangeable lens you'll discover the capability of your own camera's lens too!
Getting the best from your Lens
Firstly one of the most fundamental things you can do to get the most out of your lens is to use a lens hood. Typically made from rubber and are pliable, a lens hood attaches to the end of the lens and it also provides extra protection for the lens glass from being damaged and importantly it protects against flare from sources of light.
Lens flare is the effect caused from scattered light from the lens assembly reaching the camera's digital sensor (or film) reducing overall picture quality. Ansel Adams says in his book The Camera notes that “flare is likely to appear whenever there is a bright light source within, or just outside the picture area... [and] can usually be controlled by using an appropriate lens shade”. So develop the habit of using a lens hood aswell as keeping the lens clean and free from dust to get the best picture quality from your lens.
Short focal Length Lenses (Wide Angle, 50mm- )
Short focal length lenses, also known as wide angle lenses have a 65+ degree angle of view (how much the lens can see). These lenses are great for capturing a great deal in a scene, as they encompass much more into the picture. Because of this they are known as a fast lens, they let in plenty of light so can tolerate subject movement and camera “shake” very well and are a great choice for using low shutter speeds. A wide angle lens also have an excellent depth of field. These lenses are great for capturing a broad landscape scene or architecture.
Normal Focal Length Lens (50mm+)
A normal focal length lens have a 50 to 55 degree angle of view and are close to what would be normal human vision. These are the fastest type of lens, fast being that they have a large maximum aperture e.g. f/2.8 etc. and some have macro capability so you can get in close to the subject too.
Long Focal length Lens (Telephoto, 100mm+)
Long focal length or telephoto lens incorporate a 35- degree of angle of view. These lenses will feel like you've zoomed in from your normal vision and so distant objects will feel much closer, as the lens has enlarged the object.
Care is needed for using a lens at these longer focal lengths, as the lens extends enlarging power, movement form the camera as you hold it is also shown much more easily. Longer focal lengths also mean less depth of field, so less of your picture will appear to be focussed. Using smaller apertures are important to getting a good picture but also faster shutter speeds are important for preventing camera shake. It's best to use a support to keep the camera still like a tripod or mono-pod when working with longer focal lengths.
