BT-100-45 Basic Operation

Thank you for your purchase of the Oberwerk 45° 100mm Binocular Telescope.  This unique product provides exceptionally-high quality viewing for terrestrial and astronomical usage, using industry-standard 1.25” telescope eyepieces.  Here are some helpful tips to get you started-

  • The fork-mount ships in two pieces.  Attach the fork to the pedestal base using the 4 screws.  Note that the tensioner knobs for the fork and the pedestal should be on the same side, as shown in the picture to the left.

    Silver knob on fork base must be on same side as silver knob on upper fork.

    Silver knob on fork base must be on same side as silver knob on upper fork.

  • When attaching the fork-mount to the tripod, note the two tabs at the base of the fork. These line up with the two slots on the top of the tripod.  Insert the tabs into the slots (may be a tight fit), then tighten down the locking collar to firmly clamp the fork to the tripod.
  • When adjusting tripod height, make sure the tripod’s leg lock knobs are tight enough to prevent slippage (which could cause the binocular to become unbalanced and topple over).
  • When placing the binocular on the fork-mount, the inner “U” of fork should be level.  Set binocular on fork, being careful to not scratch the sides of the binocular on the fork (the clearance is tight).  Keep one hand on the binocular while tightening the thumbscrew underneath, until it is fully tight.
  • When inserting (or removing) eyepieces into the focusers, do so with a slight clock-wise twist.  This helps the eyepieces glide past the focuser’s internal O-rings.  Eyepieces can fit very snugly into the focusers, especially when new.  Make sure eyepieces are fully seated in the focusers.
  • The finder-scope is found in a small compartment in the bottom of the binocular case.  Simply place in the mounting block on the top left on the binocular and tighten the two thumbscrews.  The finder-scope can be focused by turning the knurled ring on the eyepiece.  Use the wide-view finder-scope to quickly point the binocular at an object of interest.  This avoids hunting for something when viewing through the binocular’s much higher-power eyepieces.
  • When viewing through the binocular for the first time, set the IPD (inter-pupillary distance) to match your eye spacing by twisting the prism housings (the “black cans”) together or apart, until you get a well-merged image with both eyes.
  • Focus one eye at a time by turning the large knurled focus rings in between the prism housings and the eyepieces.   The focuser moves outward to focus more closely, inward to focus at a greater distance.
  • While most windows do not degrade image quality, some do.  If image quality is not good, move the binocular to another window.  Avoid windows with screens.  If not sure if window is degrading image quality, point binocular toward an open exterior door, or move outdoors, to see if image quality improves.

 NOTE: This binocular is not weatherproof, do not leave it outdoors if there is any chance of rain, unless you are using our weatherproof cover.