SailNet Community - View Single Post - Binocular Conundrum: Field of View?
View Single Post
post #9 of Old 06-23-2013
Old as Dirt!
svHyLyte's Avatar
Join Date: Nov 2008
Location: Tampa Bay Area
Posts: 3,175
Thanks: 20
Thanked 152 Times in 144 Posts
Rep Power: 9
Re: Binocular Conundrum: Field of View?

Originally Posted by hellosailor View Post

I'm still not understanding this. First off, I'll assume when you say the length between the front and rear lens you mean the length of the optical path, since that can be folded differently. But even so, if the magnification is the same, and the size of the image coming out the back is the same (as measured by the exit pupil), then the distance shouldn't matter.
It is the included angle of the cone of light between the objective lens and the pupil lens that dictates the width of the field of view. Magnification has nothing to do with it at all. If you disbelieve me, touch your index finger to your thumb and hold the resulting loop against one of your eyse and close the other. Then notice how much you can see through the loop of your fingers. Then slowly extend your hand/the loop of your fingers away from your eye and continue to observe what you can see through the loop of your fingers as you move your hand. The further your hand is from your (open) eye, the less you will see through the loop of your fingers as your "field of vision" narrows as the distance between your eye and hand increases--i.e., your "cone of vision" becomes more narrow.

Here Homer Nods...

"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."

Last edited by svHyLyte; 06-23-2013 at 08:09 PM.
svHyLyte is offline  
Quote Share with Facebook
For the best viewing experience please update your browser to Google Chrome