Clear-View Horizon Mirror; Star Elongation Lens, Astigmatizer - CASSENS & PLATH POLARIS Handhabung

POLARIS Sextant
_______________________________________________________________ Page 8

Clear-view Horizon Mirror

The clear-view mirror combines the advantages of traditional split-view mirror and fullview mirror.
Same as the fullview mirror it posses a semi light transmitting area in the middle. This allows star
observations same as with the fullview mirror. The side areas without any silver coating allow free
horizon view. This is helpful in case of poor brightness conditions at dawn for example. Fixed star
or planet observations can thus be extended in time and reliability and safety of position finding will
be improved.
Therefore the POLARIS sextant is recommended for experienced navigators who want to take
advantage of twilight observations with its multiple measurements to avoid the shift of line of
positions caused by sailings.

Star Elongation Lens, Astigmatizer

Can be turned into the field of view if wanted.
The star elongation lens spreads the punctual image of the star to a horizontal light stripe. This
allows orientating the sextant so that this light stripe is parallel to the horizon at measurement.
"Swinging the arc" to find the right vertical orientation of the sextant is not longer necessary (ref. to
"Celestial Observations").
In addition dot like stars are more difficult to observe from an ergonomic piont of view than these
horizontal light stripes.
Half silvered middle area:
Easy star observations because of fullview
coating
Non-silvered side areas:
Free horizon view even under poor
brightness conditions (for example dawn)
Instructions
Astigmatizer