A lens can be of fixed focal length which is called a prime lens, or it can be a variable focal length such as a telephoto lens. A variable focal length lens has a range in mm printed on it. For example, if you bought a lens with 55-200mm on it, this indicates that this a telephoto lens with the focal length range of between 55mm and 200mm. A standard or normal lens is usually in the range of 35-70mm; a standard telephoto lens has a range of 70-135mm; a telephoto lens has a range of between 135 - 300mm, and any thing beyond 600mm in focal length is usually classed as a super telephoto lens. Therefore, a lens with a longer focal length allows you to get closer to the subject.

If you want to make you subject look bigger and fill the frame, you can of course just move closer to the subject. There are occasions however, when we need to use a telephoto lens for example, to avoid scaring the wildlife away or to avoid risky situations. This article looks at how and when to use a telephoto lens.

Sports event shots rely heavily on close ups of the action and good shots can be achieved with a telephoto lens and fast shutter speeds. Some panning with slower shutter speeds may be needed to capture the sense of speed and motion. When panning, half press the shutter release button to focus on your subject and then move the camera in synch, fully pressing the shutter release to capture the shot you want.

Getting closer to your subject is the number one reason you will want to use a telephoto lens. It can also be used in candid street photography to capture moments when people are unaware that they are being photographed. Photographing the moon is a popular past time and with a bit of care, usable photos can be achieved with a telephoto lens, a tripod and a cable release. Some post processing may be needed to bring out details. Remember though that the moon is probably the brightest object in the sky and you may need to decrease the aperture size to get the correct exposure. I have used f11 with success.

Sighting your subject when using a telephoto lens can be extremely difficult if the object is small and moving fast. Learn to sight just above the lens when moving the camera and then when you locate your subject, look through the viewfinder to focus and capture the shot. Not easy at first but with practice, it becomes second nature.

By using a telephoto lens, you can isolate your subject, making it the focus of your photo. You can isolate the mountain in the background or that amazing sunrise, removing the rest of the landscape in the process. This isolation of a subject can be used to good advantage in portrait photography which allows for a tight crop for a head and shoulders shot. Your subjects are usually more comfortable when you are not quite as close as when you are using a 50mm lens. This also produces more natural looking portraits with the added advantage that with a large aperture setting, the background can be thrown out of focus.

The best results for the average photographer in getting pin point focused photos are obtained by using autofocus, i.e. letting the camera and lens do the work for you. This works well most of the time but occasionally, such as in low light conditions, in scenes with insufficient contrasting elements, or shooting small subjects far away, the auto focus isn't up to it. You can hear the motor hunting for something to focus on. In this instance, I recommend you switch over to manual focus and fine tune the focus yourself. Using live view and the zoom control can assist you to achieve good results, as described earlier in this article.

There are, however, some problems associated with the use of telephoto lens, particularly in low lighting when a slower shutter speed is warranted. You may want to try shooting with a higher ISO or using flash where you can. The longer the focal length of the lens, the more chance there is of camera shake. It is best to use faster shutter speeds and a tripod to prevent camera shake. A simple rule of thumb is that the shutter speed should be higher than the focal length. For example, a shutter speed of 1/250s or more is needed for a lens with a focal length of 200mm. Additionally, camera shake can be caused by just pressing the shutter release button. A cable release, a remote or the camera's self timer helps out in these situations.

Using a telephoto lens in the heat of the day is known to distort images from the blurring effect of heat waves over your image. This can be exacerbated when you require pin point accuracy in focusing. A tip that I picked up when trying to focus on objects far away with a telephoto lens involves the use of the live view, if your camera has one, and the zoom control. While looking at the live view at your subject press the zoom control (that's the button with a magnifying glass with a + sign it) until you achieve a reasonably sized subject image and then fine tune your focus on the telephoto lens. Zoom back out and capture the shot. A tripod is needed for this method but it does allow for pin point focusing. Also be aware that using a telephoto lens gives a narrow field of view. Bright light outside of your image area can affect your image causing flare, which reduces contrast. The best way to deal with this is to attach a lens hood.

For further information about wildlife photography, pet photography or general questions about digital photography, visit http://photopress.in/brianparkin and http://portraitsforpets.biz/

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