What Is Optical Zoom

Michele Wanke
red rose
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If you are in the market for a new digital camera, you might be asking, "What is optical zoom?"

What Is Optical Zoom?

Optical zoom is a feature unique to compact digital cameras. It is also referred to as a "true zoom," as it changes a lens' focal length and magnification by physically extending and retracting the lens. This zooming action usually takes place inside the camera, but can often be heard making a sound similar to a small motor.

Optical zoom magnifies an object anywhere from two to 24 times its actual size. Ultra-compact digital cameras and most camera phones come equipped with three times (3x) optical zoom features, while some digital point-and-shoot cameras include ten times (10x) optical zoom. A digital camera that features a three times optical zoom can magnify an object three times larger than it appears with the naked eye. Most photographers agree that having a three times optical zoom is the absolute minimum requirement for compact digital cameras.

Benefits of Optical Zoom

The main purposes of having a camera with optical zoom is to help eliminate unwanted backgrounds in photos and to get clear shots of objects without physically moving closer to them. However, there are additional benefits to using a camera's optical zoom feature.

Excellent Image Resolution

Optical zoom does not compromise resolution when magnifying an image. Consequently, the quality and clarity of your images are not lost when zooming in to capture a specific subject. This is not always the case when shooting with a camera that features digital zoom. With digital zoom, the camera crops the existing image on the sensor--reducing the number of pixels that compose the image. This subsequently reduces image quality. Optical zoom does not compromise image quality because it uses internal glass elements of the lens to bring an image closer at full resolution. Meaning, if you have an eight-megapixel camera, and you employ its optical zoom feature you will always have eight megapixels available when documenting your image. However, if you are shooting with a digital zoom, images tend to suffer slight to moderate distortion. In most cases, a shot taken with digital zoom will appear fuzzier since the camera is essentially guessing how the picture should look while zoomed in.

Ease of Use

Optical zoom is very easy to operate. It doesn't require pressing a series of buttons to activate; rather it is built into the camera and is always active. In addition, you don't have to worry about turning the zoom on and off. Most optical zooms are activated with a toggle or slider located on the top of the camera near the shutter button. Other digital cameras feature optical zoom buttons on the backside right corner of the camera.

Convenience

Since optical zoom works by moving various elements within the camera's lens, you don't have to worry about lugging around a collection of cumbersome lenses. This is extremely convenient if you are an amateur photographer who likes to tote his camera around to various events, but doesn't want the hassle of having to pack a ton of extra gear. In addition, since the optical zoom is built into the camera, there is no need to change lenses or add on camera attachments to make the lens zoom. By defining what is optical zoom, you will be better able to wade through the hundreds of digital cameras on the market and find one that best suits your shooting style.

What Is Optical Zoom