View Single Post
Old June 23rd 04, 10:15 PM
Gareth Slee
external usenet poster
Posts: n/a
Default Zoom Question

Jim Townsend wrote:
All things being equal.. The longer the focal width, the narrower the
field of view and the closer objects appear.

Of the two lenses you listed, the 8-80mm lens provides the longest
focal length and will provide the greatest magnification.

Note that the X in zoom lens doesn't represent the magnifying
power the way telescopes and binoculars do.

The 'X' represents the difference between maximum and minimum
focal length. The X of a zoom lens is determined by dividing the
maximum focal length by the minimum.

72 / 6 = 12x (from 6mm you can increase the focal length 12x)
80 / 8 = 10x (from 8mm you can increase the focal length 10x)

If they made a 2mm to 50mm lens, it would be a 25X lens, but
wouldn't have near the magnifying power of the 8-80mm 10X lens..

Thanks Jim
That's cleared it up.

Gareth Slee

Stupid gravity!
Homer Simpson: (Falling out of treehouse)