Lenses

According to Robert Capa, 'If your photographs are not good enough, you are not close enough.'

As one of the most renowned war photographers I wouldn't always follow his advice but Capa may have a point!

Photography is not all about the camera. Although a nice high specification camera is good to have it's not necessarily the most important part of your kit. Whether you are using a point and shoot camera or an SLR, the lens is what you need to look at closely because the image that is recorded by the film is formed by the lens. A good lens will give not just better resolution and better contrast but the quality that makes a picture seem more 3-dimensional and real. As well as the manufacturers own lenses there are some excellent independent lenses so you can choose between Canon, Nikon, Sigma and others.

Putting lenses onto cameras is not quite as simple as it was. If you are using digital equipment it is worth remembering that focal lengths may differ. Most digital SLR cameras are not full frame so a conversion must be made. For instance an 18-55mm lens on the Canon EOS 20d will become approximately 27-80mm as it is multiplied by one and a half times but figures are always quoted in the analogue standard to avoid confusion. There are full frame models on the market such as the Nikon D2x but it is always worth checking first.

Lenses are usually one of two types, fixed focal length (35mm, 50 mm, 135mm, etc.), these are also known as 'prime' lenses or zoom lenses (35-80mm, 80-210mm, etc.). Some lenses which are used for different types of photography are as follows:

Wide angle lens for 35mm film. A wide angle lens is generally considered anything with a focal length of 35mm or less. These can distort perspective within the image so that straight lines may not appear so in the final photograph. Distortion will become more evident the wider the angle of the lens, you will probably start to notice it with lenses of 20mm and less.

A standard lens does not produce any wide-angle or telephoto distortion. A photo taken with a 'normal' lens will appear to have no unusual perspective. For a camera using 35mm film, a 50mm lens is considered standard and these are commonly used with older manual cameras.

Telephoto lenses are high-magnification devices. These are for when you are photographing something from far away either because you want to flatten perspective or because you are unable to approach your subject. These can be some of the most expensive lenses in the market but that is for a reason. When photographing sports and wildlife a fast aperture telephoto lens can make the difference between a good photo a great photo!

Zoom lenses in general are the most commonly used, this is because they allow you to use different focal lengths without changing lenses. If you buy an SLR camera kit then it will often have a zoom lens included. They vary greatly and can be in focal lengths from 28-80mm upto 50-500mm. Being able to use just one lens that will cover such a large spectrum of focal lengths has obvious advantages over using several smaller zooms or prime lenses, although some of these ‘all-in-ones’ can be quite heavy and slower than their individual counterparts. So why not use them all the time? Well the image quality is not as good with a zoom lens because the margin of error is increased due to the elements having to cover a much wider range of distances  This may mean the photographer will need to use a tripod to help steady themselves.

A teleconverter is a small lightweight attachment that will increase the magnification of a lens, while reducing its effective aperture. So a 2X teleconverter turns a 300/2.8 into a 600/5.6. With a typical zoom lens, you'll get vignetting (darkening of the corners) when using a teleconverter. When you are working to a budget these are a good way to increase your focal length.

There are also some specialised kinds of lenses in the market such as:

Macro lenses; These offer a range of magnification from 50mm .05x (half life size) and the 90mm, 100mm, 105mm and 180mm 1.1 (life size), the latter being ideal for close up work where a long working distance is required.. All of these lenses are capable of very close ‘subject to front element’ distance but can also be used for general picture taking. For extreme close-ups, magnifications of 1x to 5x Lifesize can be achieved with the 65mm 2.8 by Canon, a lens used primarily for specialist macro photography. Macro lenses can be costly and a cheaper alternative for increasing magnification is to use ‘close up filters’ which attach to the front of any standard lens but these do not give the quality of an actual lens.

Tilt and shift lenses; By ‘tilting’ or ‘shifting’ the lens elements, distortions caused by the convergence of straight lines (usually associated with photographing buildings) can be corrected. Another advantage of using these lenses is that they can alter the area of sharpness resulting in a more accurate interpretation of the image.

First of all knowledge of aperture will help you to bring out a good photograph from your camera because the maximum aperture determine the luminosity of the lens. Bright lenses allow fast autofocus and fast shutter speed; they give a brighter image into viewfinder, too. Slow lenses are much cheaper but they are also slower and darker.

There are lenses for all situations and occasions, from ultra wide to super telephoto. They are produced as Zooms or Prime lenses for Autofocus or Manual operation and, depending on the aperture, can be fast or slow - the wider the aperture the faster the lens. They are constructed from different materials with various lens coatings which can determine weight, quality and price. All lenses are normally interchangeable within their own camera systems and independent manufacturers make lenses to fit most cameras.

Basic knowledge of equipment essential for the person who is going to click the photograph so whether its a camera or a lens the final photograph is a combination of several other things so its better to learn how to use particular equipment and where it could give its best performance. This comes with experience!

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