The 25x81 BT81S-A Astronomical Binocular from Vixen Optics is an astronomical observation binocular with interchangeable eyepieces providing exceptional terrestrial or celestial observing. The twin 480mm f/5.9 achromatic refractors have permanently attached 45° diagonals. They accept the entire lineup of Vixen NPL Plossl eyepieces and have an enormous 56-101mm interpupillary adjustment range to work with nearly any set of eyes, including many children's.
For remarkable depth perception and contrast, there is nothing that beats the ease and comfort of erect image binocular viewing. Expect high quality observing of terrestrial vistas and celestial views alike, in a package which is easily transported to your favorite dark sky location out and beyond. Take a drive to nowhere on a clear, new moon lit night and be awe struck! The Pleiades and the Moon's terminator never looked like this.
This permutation of the BT81S-A arrives complete with two NPL Plossl 25mm eyepieces. The eyepieces are fully multicoated with pop-up eyecups. A full size, stable and sturdy aluminum Vixen Optics HAL130-SX tripod is included as is a swing arm and fork mount presenting a full astronomical package ready to peruse the celestial seas.
Twin 480 mm f/5.9 achromatic refractor telescopes with 45° incorporated erect image diagonals
AAoV of 50°
Interpupillary distance adjustment range of 2.2-4.0"