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Astronomy Binoculars

74304 BT81S-A

BT81S-A Review This 81mm astronomy binocular delivers crystal clear, sharp views through its new optical design. Its lightweight body ensures that you can take it to any observing location.

The air-spaced doublet optics in this 81mm are magnesium fluoride coated to help reduce the effects of chromatic aberration.

Mounting the binoculars is a simple process as they come supplied with a Vixen dovetail mounting bar for use with equatorial or altaz mounts. The dovetail bar also has 1/4" thread sockets for use with conventional tripod panheads.

An optional altaz fork mount is available and allows the binoculars to be used on the optional SX-HAL130 or SXG-HAL130 tripods. These provide a stable but lightweight tripod base for this excellent "space binocular".

 

Model BT81S-A
Objective lens D=81mm F=480mm Achromatic, single coating with Mgfl
Limiting magnitude 11.3
Light gathering power 134x
Dimensions L480 x W190 x H155mm
Weight 4.1kg (9lb)
Visual back 31.7mm push fit
Eyepieces (optional) SLV and LVW with 31.7mm are recommended excluding LV8-24 Zoom
Accessories included Finder bracket shoe, carry handle & dew shields

 

Note: The BT81S-A is not designed for viewing at high magnification. Use of eyepieces with focal length shorter than 10mm is not recommended. Eyepieces are not supplied as standard with the BT81S-A.

 

Optional Accessories

Fork Mount
78062 HF2 Fork Mount
Provides an easy-to-use friction controlled altazimuthal mounting for the Vixen range of astronomy binoculars and other optical devices. The fork mount comes complete with a half-pillar to raise the binoculars to a comfortable viewing height. Fits onto the SXG-HAL130 or SXG-AL130 tripods. (73798 Swing Bracket required for use with BT-ED70S-A and BT81S-A.)
Weight: 3.4kg
Maximum loading weight: 13kg
73798 Swing Bracket for HF2 Mount
Required to allow the 78062 Fork Mount to be used with astronomy binoculars and any other optical devices which have a 1/4" screw thread socket.