The Visionary B4 range of binoculars provide excellent value for money featuring high quality BAK4 prisms and multicoated lenses with excelent definition and clarity, the B4 range has a model suitable for most applications.
BAK4 prisms ensure a brighter image throughout the range of magnifications by maximising light transmission. Efficient use of the light gathered is particularly important at high magnifications or when using smaller front lenses, as images appear darker.
The lever zoom mechanism of the 8-25×50 model provides effortless control of the variable magnification. The lower magnification of 8x allows easy tracking of moving objects. The variable magnification allows the user to then zoom in for a more detailed image with little or no need for refocusing. A Zoom binocular is considered well suited for plane and aircraft spotting as the higher levels of magnification allows good levels of detail to be observed over long distances.
The level of magnification this binocular may be too high for some people to comfortably use without tripod mounting. 20x magnification is also a popular model for viewing ships off the coast and landscape viewing.