Company Seven | Advantages of the Apo Televid 77 Telescope Objective Lens Design

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Advantages of the Apo Televid 77 Telescope Objective Lens Design

Unlike most conventional spotting telescope, the Apo-Televid contains a triplet (three) objective lens instead of the two element (achromatic) design. Furthermore, optical and mechanical elements including high grade fluoride glasses with special coatings and extremely precise mounts are incorporated - all created to experience nature in its purest form.

: highly precise, three element optical system with fluoride glasses with partial anomalous dispersion
: precision mechanics maintain critical alignment of optical elements and withstand shocks of common use
: high contrast rendition
: corrected apochromatically to the edges of the field of view; no color fringing
: optimal rendition of the finest details in favorable and unfavorable ambient lighting

The fluoride glasses with extremely high light transmission that are used in the Leica Apo Televid spotting telescopes are fabricated individually, and then coated in a highly specialized process designed to minimize stress and provide best possible anti-reflective (and therefore best light transmission through the lens) characteristics. Designs and techniques gleaned through many years of Leica experience with such materials has evolved into a rigorous mounting technology that assures precise centering and survivability of the lens elements: a highly worthwhile effort for telescopes designed to withstand extremes of shock and environment.

Perfect apochromatic lens design and fabrication results in a level of correction that reduces image aberrations to an imperceptible minimum. This provides the observer with an image rich in contrast and pure in color fidelity.

Especially in difficult light conditions such as a humid overcast day, or when observing at high magnifications, the application of optical glasses with partial anomalous dispersion eliminates annoying (false) color fringes from reaching the human eye. This false color may appear as a fringe or violet halo often seen around a black bird, or even on a dark branch contrasted against the lighter sky. Such false color is typical in lesser achromatic telescopes, especially when operating them at higher magnifications or in poor lighting; this indicates that all available colors do not come to focus - in effect this produces a loss of contrast and detail, color shifts, and resultant loss of apparent brightness.

Such distractions are eliminated in the "apochromat" telescope. The finest structural details are also enhanced, even when contrast is high. In other words, wherever there is a lot of light and shadows.

Leica eyepieces extend the outstanding apochromatic correction all the way to the outermost borders of the image: "Brilliant to the very tips of their wings!".