The 25x81 BT81S-A Astronomical Binocular w/ 2 NPL25 Eyepieces 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 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 with two Vixen 25mm NPL Plössl eyepieces. The eyepieces are fully multicoated with pop-up eyecups. A required mount and a tripod or base need to be supplied by the user.
- AAoV of 50°
- Accepts multiple 1.25" eyepieces
- Visual back 31.7 mm - friction fit
- Built-in carry handle and finder bracket
- Mount block dovetail bar for SX/GP tripods
- Interpupillary distance adjustment range of 2.2-4.0"
- Two fully multicoated Vixen 25mm NPL Plössl eyepieces with pop-up eyecups
- Twin 480 mm f/5.9 achromatic refractor telescopes with 45° incorporated erect image diagonals