The Importance of a Good Camera Lens

The two major components of digital cameras that play a big part in image quality are the image sensor and the lens.  Get the best you can afford since good quality lenses are essential for getting the best pictures and hence the most out of your digital camera enjoyment.

Lenses come in various focal lengths which determine two things: Field of view and depth of focus. As they become longer they can focus on smaller areas but require more precise focusing to obtain a sharp image. My camera loses picture sharpness as I zoom in with the telephoto lens.

When shopping for my next camera I will be more careful to find a camera that maintains a sharp picture no matter how much I extend the telephoto lens.

When shopping for a telephoto lens keep in mind that longer lenses are more susceptible to movement and will likely blur images if the camera is moved during a shot, similar to zooming in on a subject when using a video camera. The image doesn't blur, but every little movement is exaggerated.

Long lenses are sometimes called telephoto lenses. The images shot with telephoto lenses are magnified compared with shorter lenses because of their reduced field of view. Similarly, shorter lenses give a wider field of view, so very short lenses are called wide-angle lenses.

A 'normal' lens is one that produces an image similar to what the human eye sees. There is no standard length for a normal lens because field of view is directly connected with the size of the image sensor that captures the photo.

This is interesting: A 50mm lens is considered normal for traditional 35mm cameras but digital image sensors are much smaller than a frame of 35mm film, so shorter lenses on digital cameras will capture the same field of view as the 50mm lens on a 35mm camera. If you grew up using a 35mm camera, you may have wondered how the numbers compared.

If you are really familiar with a 35mm camera, you might want to find a digital camera that includes a reference to how the two cameras compare in regards to focal length. Digital cameras will often include this reference, although not every camera does.

Almost every digital camera has an optical zoom function that changes the focal length of the lens. They are rated as a multiplier – a 3X zoom will enlarge or reduce an image by 3 times from the longest to the shortest setting.

Some cameras are also equipped with a digital zoom. These work by cropping the image digitally and then spreading the result over all the photosites on the image sensor.

When shopping for a digital camera keep in mind that a digital zoom is inferior to optical zoom and should not be used. Better results can be obtained by editing the photo using computer software.

Most digital cameras in the mid-range and better have the ability to add lens converters. By giving you the ability to attach various types of lenses and filters, these cameras give you more options for digital photography.

In addition, lenses made for film cameras can be accepted by many digital cameras. However, because of the difference in size between film and image sensors these lenses do not produce the same results as they do with film cameras. A telephoto lens designed for film will have a larger magnifying effect, and a wide angle lens will have less effect on a digital camera.

Lenses are quite expensive and should be cared for to keep them in working order. To protect your investment you should keep them in cases and covered with caps when not in use. Most lenses come with caps but you may have to buy extras in case they are lost. The caps are widely available and fairly inexpensive.

Lens hoods are useful for controlling the amount of light entering the lens. They result in images that have less contrast and so can be useful for some outdoor situations.

Lens cleaning kits are available but should be used as infrequently as possible. It is extremely important to avoid touching the lens with your fingers as the oils in your skin can cause permanent damage to the lens coating.

Wipe fingerprints with a soft cloth but first remove dust particles with a blower. Larger dust can be removed with a soft brush. These precautions will help protect the lens from any scratches.

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