Zoom binoculars offer the user a range of magnifications. The zoom function can be operated by hand using a lever, or by switch when driven by a motor. Zoom systems vary by model.
Waterproof binoculars and
Style of Binoculars – Porro or Roof Prism Design
Binoculars come in two distinct styles in which design is dependent upon the type of prism system used. The image that passes through a binocular is upside down (a function of the lens) and needs to be corrected. This prism is the optical glass inside a binocular whose purpose is to “invert” the image.
eyepiece
Roof Prism System: the prisms overlap closely allowing the objective (front) lens to line up directly with the eyepieces. The result is a slim, streamlined shape in which the lenses and prisms that magnify and correct the image are in a straight line.
