For most people, the thought of buying a camera lens can be intimidating, and they'd rather leave the job to the salesperson at the camera shop to help make their choice. However, if your love for photography is that big as to warrant you getting an extra camera lens for your camera, it may be worthwhile knowing a little bit about what you should be looking for.
This is particularly important if you want to be in a position to compare different lenses.Types of Camera Lens
When you are ready to take your picture-taking skills to another level, then an interchangeable camera lens could be what you need. Depending on the type of pictures you intend to take, an idea of the type of camera lens to buy is very necessary. There are standard, wide angle or telephoto lenses that will suit different purposes.
If you're just interested in taking pictures of family and holiday shots, a standard camera will probably be good enough. A standard camera generally mimics an image as seen by the eye. To improve on the standard camera lens, you could consider a wide angle camera or lens that will take pictures at a wide angle. These are perfect for taking pictures of landscape, outdoor events and tourist attractions etc. If you often find yourself in situations that require zooming in from long distances, a telephoto lens may be what you need. These are usually ideal for sporting events and also tourist photos.
Focal Length
The focal length is the distance between the optical centre and the focal plane of a lens. The importance of knowing the focal length is that it determines the angle of view. There is an inverse relationship between the focal length and the angle of view. The shorter the focal length, the wider the angle of view, which translates to more of the image that can be captured. When the focal length is reduced, the less of the image that is seen, and the image grows larger and closer.
In photography, a 50mm lens is considered normal as it almost replicates the field of view of the human eye. Wide angle lenses range between 16-35mm. Note however that if you have a DSLR camera, a little bit of understanding of focal length is required, as they work a little differently. It will be useful to also understand the crop-factor and the focal length.
Aperture
This refers to the amount of light that will reach the focal plane and has an implication on brightness. Generally, smaller apertures allow in more light, which offers better control, ie with more light, shutter speed is increased. Faster shutter speeds can be useful when shooting in low light. With zoom lenses, the maximum aperture will be indicated as a range. When buying a lens, look for the best apertures, keeping in mind that the faster ones are usually heavier than the slower ones. As such, it's a trade-off between getting faster shutter-speeds and how comfortable you'd feel carrying a heavy camera lens. If you're wondering how to find the aperture setting - it's normally written on the lens barrel along with the focal length.
Zoom and Prime Lens
Most camera lenses you'll find in the market are zoom lenses. These lenses are very convenient as they offer the ability to choose different focal lengths. This also means that there'll be no need to switch lenses to achieve different focal lengths. Different lenses have different options and prices, and if in doubt you could check a manufacturer's or review sites for details. A word of caution - make sure that any lens you are considering buying is compatible with your camera before you buy!
If you're a photography expert, then you may feel comfortable using prime lenses that offer fixed focal lengths. Some photographers prefer a particular style of shooting. Obviously, this will vary from photographer to photographer.
Image Stabilisation (IS)
There are many camera lenses with the in- built function of image stabilisation. This function ensures that once the lens is mounted on any camera, images are stabilised, hence taking care of unintended movement or shaky hands. If you're looking for a lens with image-stabilisation, make sure you buy one that has this feature specified. It may be easy to know just by looking at the camera lens, as some manufacturers will use names like IS. The notation used to denote this function will vary from manufacturer to manufacturer, so knowing the terms used by different manufacturers can also be useful.
Compare Prices
You may be surprised at the huge difference in prices that cameras with seemingly the same focal lengths may have. However, the difference in price is mostly due to the difference in aperture. How wide the aperture opens is denoted by f/stops. Lower apertures will generally do better in low light. Always shop smart to ensure you get exactly what you need and not what you want!
