Vixen BT80M User Manual
Vixen Optical devices
VIXEN BT80M-A BINOCULAR TELESCOPE
Eyepiece
Eyepiece Lock Ring
Focusing Ring
Prism Housing
Diagonal Prism Housing
Photo Tripod Adapter
Objective Lens
Lens Shade
Body Tube
Handle
Vixen BT80M-A Specifications:
Objective
Performance
Aperture
80mm
Magnification
36x
Focal Length
900mm
Angular field of view
1.11
Aperture Ratio
1:11.2
Linear Field of View
19m at 1000m
Optical Composition
2 Air spaced compo-
nents with built in tele-
extender
Exit Pupil
2.22m
Magnification can be changed by using other op-
tional Vixen NLV Eyepieces
Coatings
Magenta coated
Eyepiece
Measurements
Optical Composition
2 group - 4 element
OR25mm
Size
23 in x 7.5 in x 8.5 in
(58cm x 19cm x 21.5cm)
Coatings
Multi Coated
Weight
11 lbs (5kg)
Using your BT80M-A Vixen Binocular Telescope
1. To install on a photo tripod, screw the photo tripod adapter on the pan head of the tripod.
2. Aligning 3 Dots: Align the three dots marked on the eyepiece, focusing ring and prism housing in
red for the right side of the binocular telescope and in green for the left side. Optical axis is now
collimated and focus is adjusted to infinity.
3. Adjust the inter pupillary distance: Hold the right and left prism housings with your hand and
look through the binocular telescope while turning them until one clear circle of image is seen.
4. Focusing: Close your left eye and look through the right eyepiece with your right eye. Rotate the
focusing ring of the right eyepiece until the image appears in sharp focus. Next, close your right
eye and look through the left eyepiece with your left eye. Rotate the focusing ring of the left
eyepiece until the image appears in sharp focus.