Can some biniculars have variable feild of view?

Question

like for example, 5x, 10x, 15x on the same binoculars

can some telescopes do?

Answer 1

There are zoom binoculars.  The field of view shrinks as you zoom in to higher magnification.

Most telescopes use eyepieces that can be quickly switched.  I have three on my 10" telescope, giving 48x, 120x and 240x magnification.  The field of view reduces accordingly.  There are zooming eyepieces, but they are not very common.

But i also have a spotting scope that has only one eyepiece.  It is fixed at 22x, about 3.5 degrees field of view.

I've been happier with binoculars and spotting scopes that do not have a zoom feature, in general.  The zoom feature is very expensive to get right, and most of the time, the feature is poorly implemented to reduce cost.  My $250 spotting scope is better than most of the $1200 zoom spotting scopes i've checked out.  And the 100 giant zoom binoculars i tried out at the store were so badly out of alignment as to be worthless.

It's even more complicated that this for telescopes.  Two eyepieces with the same focal length will give you the same magnification on the same scope.  But different designs may give you different field of view as a result.  Typically, wide field of view eyepieces are very expensive.

Answer 2

Yes - I once had some zoom biniculars.  I used them at football games, but later switched to a smaller unit that doesn't zoom.

Answer 3

Zoom binoculars are variable field binoculars.Telescope can change eye pieces of different focal length and have different fields. When you zoom to higher magnification,your field reduces.But they are not very good for Astronomical use.

Answer 4

I think I've heard of binoculars that you can zoom with.  And for telescopes, some of the expensive ones probably have zoom, but my friend had a cheap one and you could just change the eyepiece to zoom in farther.  Video cameras are good for this too--my camera (a $250 Sony Handycam) zooms in to 990x--farther than most microscopes and telescopes I've seen.  It's great for lunar eclipses, as long as you have a tripod.

Answer 5

Just about any telescope can do this.  All you would have to do is to buy a variable power eyepice.  However most of these eyepices provide inferior images.  You are better off using low, medium, and high powered eyepieces.

Link to some of the better quality variable eyepieces:

http://www.telescopes.com/telescope-acce...

http://www.telescopes.com/telescope-eyep...

http://www.telescopes.com/telescope-acce...