Vixen GREAT POLARIS GP-DX Instruction Manual page 6

@Try to find a clear object more than 200m away. Point the
telescope toward the object after unfastening both the R. A. and
Decl. clamps.
[Note] Eyepiece angle can be adjusted for your telescope by rotating
the optical tube in the tube rings after unfastening the tube-ring
screws.
©In the beginning, everything may blur. Gradually turn the focusing
knob until your object comes into sharp focus.
©Whoops! The view is upside down, and backward! But that's
OK —all astronomical telescopes operate this way as it really
doesn't matter in space. There are special prisms that correct the
condition, but they dim the image slightly.
r
How to use a Porro Prism or 45 Erect-lrhage Diagonal Prism))
To correct the upside-down view on the refractors, use a
36.4mm porro prism or 24.5mm 45 erect-image diagonal
prism fora 24.5mm eyepiece and a 31.7mm 45 erect-image
diagonal prism
for a 31
.7mm eyepiece.
[Note]
©The other porro prisms
cannot
be used for this purpose on
the refractors because these cannot close focus.
©Any prism cannot be used on Newtonian reflectors. 24.5mm
Eyepiece
Screw in.
36.4mm Porro Prism
Push in.
Adapter 36.4mn
,7mm
Eyepiece
131 [:7pihi 45 Erect-Image
Diagonal Prism.
IHow to use a Terrestrial Eyepiece))
Although the upside-down view can be corrected with a ter¬
restrial eyepiece, it makes the field of view narrow. Also, the
magnification power of the terrestrial eyepiece cannot be
changed. The method of calculating the magnification of the
terrestrial eyepiece is the same as those of other eyepieces.
[Note)The terrestrial eyepiece cannot be used on Newtonian
reflectors.
>=
3
>
Eyepiece Adapter
Push in.
m —
Insert Barrel
Terrestrial Eyepiece
(f = 18mm)
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