It is a continuing (and annoying) puzzle to me why accessory manufacturers resist the commercial and affordable production of Filar micrometers for amateur astronomers. Their twin-threaded ability to easily measure the separation of stars or detail in the visual field, merely by turning a dial, has ensured my continued ownership of one — albeit a time-travelling refugee from a more enlightened (Victorian) age.
Rant over, there are never the less modern-day equivalents that use a reticuled eyepiece to achieve a result approaching that of the filamentary design. This 25mm eyepiece has a field cross-hatched by a reticule that permits measurement through sub-divided etched lines. The reticule’s illumination is adjustable via a large tactile knob — to match requirements of the object being observed.
Weighing in at only 131g it will not imbalance your ‘scope; and for the eye, a fold-down rubber eyecup means comfortable use is offered to normal or bespectacled observers.
Also usefully employed as a guiding eyepiece, the Polaris is fitted with a T-2 thread, although 1.25″ and 2″ nosepiece adapters are available.
For more information: www.baader-planetarium.uk.com