consideration that the position in the slots varies depending on the year. The four slots for
two of the axes are related to the observation years reported in the border of the reticle.
4. When the three star are correctly positioned in the slots tight the Altitude and Azimuth
knobs against the respective contrast blocks and,
5. At the end, firmly tight the screw that lock the mount movement respect to the tripod.
Note: In case of difficulty to correctly orientate the constellation in the right position it is
possible to get the help of a PC, smartphone or tablet applications to perform the initial
orientation of the Polaris axis, as explained below.
5.3.3 External programs for Polaris Finding
Several applications exist to help executing a good Polar Alignment using PC (Windows and
Mac) and mobile devices (iOS and Android). All of them are based on a similar concept: A
virtual reticule, often representing the real reticule present in the Polarscopes, with the position
of the Polaris in function of the observation site coordinates, the local date and time.
In this section we present an application available for iOS but with very common feature that are
easily applicable to all other applications with the same purpose.
Polar Scope Align Pro allows the choice of a large number of reticules, used by almost all
commercial mounts developed in the last ten years. The three reticules presented here represent
those discussed in the previous sections (old Skywatcher, new Skywatcher and Losmandy).
The first is the very simple Skywatcher reticule described in section 4.3.1 representing the
approximate position of the Big Dipper and Cassiopeia asterisms
Using it is very simple, rotate the RA axis until the polar-scope reticule is oriented as the virtual
one and operate on the Alt and Az Knobs to bring the Polaris inside the small circle located on
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