Binocular - Binoculars have two eyepieces
Telescope - Telescopes have one eyepiece
Ocular lens - the lens closest to the user’s eye
Objective lens - the end furthest from the user’s eye -the light-gathering lens
What does 10X50 to describe an optic mean?
-The first number- here “10-” is the power of the magnification. The second number-here “50-” is the diameter of the objective lens in mm.
Trade-offs?
The basic rule of physics is “the more you magnify the more you narrow the view”. That rule applies to all optics. therefore a 35 X power telescope has more magnification than a 10X binocular but the telescope views a much smaller “patch of space” – a view with much less breadth. If you have a scenic view you typically want the binocular view so you can take it all in.