Eyepieces And Magnification - Orion StarSeeker IV GoTo Instruction Manual

near the rear of the sight. The 3V lithium battery provides the
power for the diode.
For the EZ Finder II to work properly, it has to be aligned with
the telescope. When the two are aligned, a celestial object that
is centered on the EZ Finder II's red dot should also appear
in the center of the telescope's eyepiece. Alignment of the EZ
Finder II is easiest during daylight, before observing at night.
Aim the telescope at a distant object such as a telephone pole
or roof chimney and center it in the telescope's eyepiece. The
object should be at least 1/4 mile away. Now turn on the EZ
Finder II and look through it. Without moving the main tele-
scope, use the EZ Finder II's azimuth (left/right) and altitude
(up/down) adjustment knobs (see Figure 12) to position the
red dot on the object in the eyepiece. When the red dot is cen-
tered on the distant object, check to make sure that the object is
still centered in the telescope eyepiece. If it isn't, re-center it and
adjust the EZ Finder II's alignment again. When the object is
centered in the eyepiece and on the EZ Finder's red dot, the EZ
Finder II is properly aligned with the telescope. Once aligned,
EZ Finder II will usually hold its alignment even after being
removed and remounted. Otherwise, only minimal realignment
will be needed.
Turn the ON/OFF knob (see Figure 12) clockwise until you
hear the "click" indicating that power has been turned on. Look
through the back of the reflex sight with both eyes open to see
the red dot. Position your eye at a comfortable distance from
the back of the sight. In daylight you may need to cover the
front of the sight with your hand to be able to see the dot, which
is purposefully quite dim. The intensity of the dot is adjusted
by turning the ON/OFF knob. For best results when stargazing,
use the dimmest possible setting that allows you to see the dot
without difficulty. Typically a dimmer setting is used under dark
skies and a brighter setting is needed under light-polluted skies
or in daylight.
At the end of your observing session, be sure to turn off the ON/
OFF knob on the EZ Finder II.

Eyepieces and Magnification

Your StarSeeker IV telescope comes with two special wide-
field eyepieces, (Figure 13). Eyepieces are commonly
referred to by their focal length and barrel diameter. The focal
length of each eyepiece is typically printed on the eyepiece
body. The two eyepieces included with your telescope have a
1.25" barrel diameter. One has a focal length of 23mm and the
other, 10mm. The longer the focal length (i.e., the larger the
number), the lower the eyepiece power or magnification; and
the shorter the focal length (i.e., the smaller the number), the
higher the magnification. Generally, low or moderate power will
produce the sharpest images when viewing.
You can change the magnifying power of your telescope just by
changing the eyepiece. To determine the magnification of your
telescope, simply divide the focal length of the telescope by the
focal length of the eyepiece used.
6
Leg lock
knob
Figure 5
. Loosen the leg clamp knob to adjust the length of the
tripod legs.
Dovetail
mounting bar
Figure 6.
The telescope tube can be attached and removed easily
via the dovetail saddle on the mount arm.
Telescope Focal Length (mm)
Eyepiece Focal Length (mm)
For example, the StarSeeker IV 114mm reflector has a focal
length of 500mm, which when used with the supplied 23mm
eyepiece yields 22x magnification:
Leg
extension
Lock knob
Telescope tube
Dovetail saddle
= Magnification