High refractive index BAK4 prisms deliver a round exit pupil and a crisp and clear image with limited edge distortion Aspherical eyepiece lenses correct spherical aberration to produce clear and crisp images, with reduced edge distortion and astigmatism Traditional Porro prism light path produces a rich depth of field, allowing the user to discern the relative distances between objects in the view Traditional Porro prism light path produces a rich depth of field, allowing the user to discern the relative distances between objects in the view Wide 10-22x zoom magnification range provides wide views at low magnification, with the ability to make detailed observations of distant objects at high magnification