Optical or Digital Zoom?

Executive Summary By Ziv Haparnas

What is zoom?
There are two types of zoom - optical and digital (in older film cameras the only zoom option was optical). Optical zoom works by physically moving the camera's lenses and changing the focal length.

How does optical zoon work?

Optical zoom works by physically moving the camera's lenses and changing the focal length. By changing the focal length you can make objects appear bigger and fit the full photo frame. When satisfied with the zoom position you can shoot the photo by simply applying the shutter button.

How does digital zoom work?

You run the digital zoom software and choose a 2X zoom. To accomplish this zoom the camera crops half of the photo and enlarges the other half to create a 2X zoom effect. The result is a photo with a quality equivalent to a 1MP photo.

Digital zoom significantly reduces the quality of the photo. If your camera does not include digital zoom you can always shoot the photo without zooming and then use a PC photo editing software to crop a portion of it and enlarge the rest. In fact using PC software is always the preferred method to built-in digital zoom since it allows you to try different zoom sizes, different zoom areas and different zoom algorithms while not losing the original photo.

Optical zoom is superior to digital zoom. It is always better to apply digital zoom on a PC at a later time rather then when taking the photo using the camera's built-in digital zoom.

Know your camera's zoom

Some manufacturers claim the maximum zoom figure their cameras support without specifying if it is optical or digital zoom. For example if a camera supports a 5X optical zoom and 10X digital zoom advertising the camera as a "10X zoom camera" is confusing - 10X digital zoom can be done with any camera using simple PC software.

Digital verses Optical Zoom

Executive Summary By Stephen Orgill

Manufacturers are claiming a zoom function called digital zoom, or they are adding up the total zoom of there optical zoom and digital zoom for a total zoom function.

What is Optical Zoom?

Optical zoom is what I like to call true zoom. This function of a camera uses the lens within the camera to draw the image closer. When using optical zoom quality remains the same and the full resolution of the camera can be used on the zoomed image.

What is Digital Zoom?

Digital zoom on the other hand is not a true form of a zoom function. The idea behind digital zoom is that it takes a portion of the image and expand that image to the full size of the image.

How would you compare digital cameras

The only zoom to compare is optical zoom of one camera to the optical zoom of another.