Conventional hand-held binoculars will resolve the more widely separated double stars, whilst stabilising binoculars, as described above, are capable of dividing much closer, fainter pairs. However some form of mounting is essential if field drawing is to be attempted.
There are several types of adapter. The example illustrated in Figure 3.2 consists of a threaded clamp which is tightened around the central axis of the binoculars; the adapter base is secured to the tripod by means of a standard screw thread. An alternative design comprises an L-shaped bracket with a projecting thread at the top end; this style of adapter is suitable for binoculars that have a threaded recess at the objective end of the central axis. Large binoculars may
benefit from the extra support provided by the "heavy duty" type of clamp which fits around one side of the binocular housing, giving a more stable and rigid observing platform.
It is advisable to choose a tripod that allows binoculars to be secured at slightly above head height, preventing an uncomfortable stoop when studying objects at high altitude. Tripod legs should be strong and sturdy, otherwise any vibration will be transmitted to the field of view, resulting in a shaky image. Both tripod and adapter can be purchased from any good camera shop. Mounted binoculars are portable, easy to set up on any flat, level surface and will enhance the enjoyment of observing double stars and many other celestial features.
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