Monday, April 2, 2012

Determine The Zoom For A 75300mm Telephoto Lens

The larger the focal length, the more magnification power the lens has.


Camera lenses come in a variety of focal lengths. Lenses that can be adjusted to cover a range of focal lengths are known as zoom lenses. The zoom of a lens represents the factor by which the maximum focal length exceeds the minimum focal length. However, the zoom on a camera lens is only relative to its minimum focal length, so the zoom by itself does not tell you how far away or close to a subject you can stand when taking a picture. For that, you need to look at the focal lengths themselves.








Instructions


1. Note that the widest angle focal length of the lens is 75 mm. The widest angle focal length is represented by the smallest number in the len's focal range. This is the focal length that will zoom in the least.


2. Note that the maximum focal length of the lens is 300 mm. This is the focal length that will zoom in the most.


3. Divide the maximum focal length by the minimum focal length to find the zoom for the lens. With the 75-300 mm lens, you divide 300 by 75, which comes to four. That means that the lens can zoom in four times closer than its minimum focal length.

Tags: focal length, minimum focal, minimum focal length, focal lengths, maximum focal