Looking at Lens Features

When choosing a digital camera, the first thing you should concentrate on is the lens furnished with the camera. Understanding the basics of lens features will help you make the best choice for your needs. Some of the more expensive digital SLR (single lens reflex) cameras allow you to use interchangeable (attachment) lenses that you can use in different situations.

Evaluating lens features

Examine the following basic features of digital camera lenses:

• Focal length: The focal length of a lens is the distance between the optical center of the lens and the place where it focuses its image, and is expressed in millimeters. This determines the area of coverage from narrow to wide (see Figures 1 and 2). Digital cameras generally rate their focal lengths as equivalent to 35mm film camera lenses.

- 20mm or less = Extreme Wide Angle

- 24mm to 35mm = Wide Angle

- 50mm to 80mm = Normal

- 100mm to 300mm = Telephoto

- 400mm and above = Super Telephoto

• Macro mode or lens: This enables close-up photos of small objects. Good cameras have a macro mode built into their lenses.
• Normal lens: A normal lens is usually a 55mm focal length equivalent and is the most commonly used fixed lens.
• Wide angle: A wide angle lens is less than 35mm focal length equivalent. It allows shooting a more inclusive image in tight spaces. Lenses much wider than 28mm are referred to as fish-eye lenses because of their image distortion.
• Telephoto: Telephoto lenses have more than 55mm focal length equivalent. These usually range from 75mm to over 1000mm and are used to snap photos of subjects at a distance.
• Zoom: Zoom lenses have variable focal lengths and can be changed from wide angle to normal to telephoto. Digital cameras feature both optical and digital zooms. Optical zooms result in highest quality.
• Interchangeable: Prosumer and professional digital cameras permit the use of different lenses. These can range from wide angle to telephoto.
• Lens extenders: These are available to multiply the magnification of zoom or macro lenses. They attach to the camera's lens. Some cameras don't accept extenders.
• Filters: Better-quality cameras allow the use of filters on the end of the camera lens. These can compensate for light color differences and can create special effects.
  

Tip
Most digital cameras, from consumer to prosumer, come with nonchangeable optical zoom lenses. Most also have digital zoom features. Buy the camera with the largest zoom ratio you can afford. They range from 1.2x to 10x or more.

Using attachment lenses

The normal zoom lenses that come with digital cameras have limitations. Inexpensive consumer cameras leave you nothing to do about this but to upgrade to a better camera. More expensive digital cameras allow you to use lens extenders or to exchange lenses to expand the limits.

Attachment lenses are simple to use. First, select the attachment lens to meet your needs - wide angle, telephoto, or close-up. Then, attach the lens extender to the normal lens and shoot photos normally.

Tip
When using a wide angle extender, make sure that you set the normal zoom to the widest setting to maximize the effect. When you use telephoto adapters, set the normal zoom lens to the longest setting to maximize the telephoto effect.

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