Leupold Mark 4 Spotting Scopes

Xtended Twilight Lens System

Now your hunt can reach further into the twilight than ever before possible, with our exclusive new Xtended Twilight Lens System™. It goes a step further than even the Index Matched Lens System®, using Leupold’s® index matched glass with wavelength specific lens coatings designed to optimize the transmission of low-light wavelengths. When most scope manufacturers quote percentage of light transmission, they usually mean at 550 nm, the green wavelength where the human eye is most sensitive. The challenge is that in twilight conditions, green light disappears and blue/violet light takes over. Your eye is already handicapped when it comes to seeing the blue/violet spectrum, and if your scope is cutting too much of it out, soon you won’t be seeing anything. The Xtended Twilight Lens System places extra emphasis on matching coatings to glass indices to achieve the best possible transmission of the blue/violet spectrum, without sacrificing the color balanced light transmission across the visual spectrum of the Index Matched Lens System. When we combine that with superior computer-generated optical design, lead-free lenses of unsurpassed clarity and quality, and 100 years of manufacturing excellence, you have a scope that gives you the details of low-light scenes in greater definition and luminance than any other scope in the world.