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04/07/12(Sat)02:36 No.5682969>>5682936
It's the focal length of the lens.
Try
the following. Take your hand and place it a foot away from your face.
Focus on your hand and make sure it looks perfectly crystal clear. Now,
slowly your move your hand toward your face as you continue to pay
attention to it.
No matter how hard you try, your hand will
eventually become blurry and out of focus at a certain distance. When
this happens, you have passed the focal point of your eyes. The focal
point for your eyes is a point exactly one focal length away from the
lens in your eye. Most human eyes focus near 50 millimeters, so the
focal point is 50 millimeters away from your face.
A
wideangle lens has a smaller focal length while a telephoto lens has a
longer focal length. Typically, most wideangles start at 35mm and move
down to 1mm. Telephoto lenses start at 70mm and go as high as 1700mm.
With a wideangle, everything appears “zoomed out”, and telephoto lenses
allow us to “zoom in” as much as we want. |
