Telephoto Binocular Comparison

There are wide angle lenses, there are telephoto lenses, and what is
in-between is a normal lens. It is in reality a marketing term that is
useful for communication. It has meaning, much more meaning than image
circle = focal length for the majority of camera users.

How closely it approximates what an eye actually sees can easily be argued
but nothing is gained by that. Few people would buy a camera that created
images that were identical to the instantaneous image the eye creates.

Everyday people buy digital cameras, not knowing the image sensor size. They
have a pretty good idea what a wide angle to short telephoto zoom means.
They don't care how easy it is to design or build or if a researcher uses
the same definition for wide angle, normal, nor telephoto. They have a
pretty good idea what they want the camera to do and want to talk to other
normal people about it.

-jeff


"Nicholas O. Lindan" wrote in message
link.net...

snip snip
Balderdash. They are 'normal' because that's the optimum point for lens
design: image circle = focal length. A 'normal' lens is the lens that
'normally' comes with the camera. A 'normal' lens has now become
a plastic-element 28-80 f4.5-6.9 atrocity.

[Web sites] I browsed stated [blah, blah, blah...]
snip snip

Who do you think knows something about recreating 'normal eye
perspective' on a (nominally) 2-D surface -- some yo-yo on the
web or Boeing, Lockheed, Matsu****a, Phillips, IBM Research,
PARC ...
--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

This is not exact, but with 35mm cameras, divide the focal length of your
telephoto by 50 to get an approximate degree of magnification thus a 100mm
lens / 50 = 2 or approximately 2x magnification. (a 48mm is roughly as the
eye sees it so dividing by 50 makes a fast "rule of thumb" approximation)
Your binoculars should state the magnification on the body.
Thus 10x binoculars would be approximately equal to a 500mm telephoto.


foto wrote in message
m...
I am in the process of buying a new pair of binoculars and wondered if
there
was any way to compare the focal length of a telephoto lens to the power
rating of binoculars. It would be nice to know how the scene I am looking
at thru the binoculars relates to my lens length.