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8

Fig.e

U

sing the optional Barlow lens

A Barlow is a negative lens which increases the magnifying 
power of an eyepiece, while reducing the field of view. It 
expands the cone of the focussed light before it reaches the 
focal point, so that the telescope's focal length appears 
longer to the eyepiece.

The Barlow is inserted between the focuser and the eyepiece 
in a reflector (Fig.e). In addition to increasing magnification, 
the benefits of using a Barlow lens include improved eye 
relief, and reduced spherical aberration in the eyepiece. For 
this reason, a Barlow plus a lens often outperform a single 
lens producing the same magnification. However, its greatest 
value may be that a Barlow can potentially double the 
number of eyepiece in your collection.

F

ocusing

Fig.f

Slowly turn the focus knobs under the focuser, one way or the 
other, until the image in the eyepiece is sharp (Fig.f). The image 
usually has to be finely refocused over time, due to small 
variations caused by temperature changes, flexures, etc. This 
often happens with short focal ratio telescopes, particularly when 
they haven't yet reached outside temperature. Refocusing is 
almost always necessary when you change an eyepiece or add 
or remove a Barlow lens.

Barlow

Eyepiece

In order for your telescope to track objects in the sky you have to align your mount. This means tilting the head 
over so that it points to the North (or South) celestial pole. For people in the Northern Hemisphere this is rather 
easy as the bright star Polaris is very near the North Celestial Pole. For casual observing, rough polar alignment is 
adequate. Make sure your equatorial mount is level and the red dot finder is aligned with the telescope before 

P

olar alignment

Fig.g

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Setting the latitude

Remove the telescope tube and the counterweights from the mount. 
Find the latitude and time zone of your current location. A road atlas 
or GPS unit is useful for your local geographic coordinates. Now look 
at the side of your mount head, there you will see a scale running 
from 0-90 degrees (Fig.g). At the base of the head, just above the 
legs, are two screws (latitude adjustment t-bots)  opposite each other 
under the hinge. All you have to do is loosen one side and tighten the 
other until your latitude is shown by the indicator pointer (Fig.i). 
Loosening the front T-bolt first will make the adjustments easier. Small 
adjustments may be needed after re-attaching the telescope tube and 
the counterweights.

Polaris, the "Pole Star" is less than one degree from the North 
Celestial Pole (NCP).  Because it is not exactly at the NCP, Polaris 
appears to trace a small circle around it as the Earth rotates.  Polaris 
is offset from the NCP, toward Cassiopeia and away from the end of 
the handle of the Big Dipper (Fig.g-1).

Содержание SK P25012EQ6-2IN

Страница 1: ...SK P25012EQ6 2IN...

Страница 2: ...Newtonian reflector Cleaning Your Telescope 3 6 3 4 4 4 5 5 5 6 6 7 7 8 8 8 9 11 12 13 14 14 14 14 14 15 16 14 15 Before you begin Caution Read the entire instructions carefully before beginning Your...

Страница 3: ...unterweight Rod Lock Knob Counterweight Thumbscrew Counterweight Counterweight Rod Hand Control Finderscope Bracket Alignment Screw Focus Locking Screw Piggyback Bracket Tube Rings Pirmary Mirror Posi...

Страница 4: ...led knob underneath to secure mount to tripod Fig 3 Fig 4 Fig 5 TRIPOD SET UP Fig 2 Note Loosen the azimuth adjustment knobs if mount does not fit into tripod head completely Retighten knobs to secure...

Страница 5: ...2 Find the center of balance of the telescope tube Place this in between the two tube rings Close the hinges around the telescope and fasten securely by tightening the thumb nuts TELESCOPE ASSEMBLY Fi...

Страница 6: ...anced after all accessories eyepiece camera etc have been attached Before balancing your telescope make sure that your tripod is balanced and on a stable surface For photography point the telescope in...

Страница 7: ...ontrol buttons R A control buttons N OFF S 2X 8X 16X Dec Dec R A R A R A The N Off S switch acts as a power switch as well as controlling the directions of the motors The N position allows R A motor t...

Страница 8: ...n the sky you have to align your mount This means tilting the head over so that it points to the North or South celestial pole For people in the Northern Hemisphere this is rather easy as the bright s...

Страница 9: ...e polar alignment This method of polar alignment is sufficient for virtually all visual use of the telescope To use the Polarscope with the EQ 6 mount the declination axis must be rotated such that th...

Страница 10: ...ou should be able to align the reticle with the R A axis to within about 2 or 3 arc minutes You should never have to make this adjustment again unless the polar scope has been dropped disassembled or...

Страница 11: ...the celestial pole Due to its proper motion Polaris can be seen to move with respect to the Pole from year to year The tick marks in the Polarscope can be used to compensate for this motion Fig h 5 c...

Страница 12: ...DEC lock knobs to lock the mount in place Now rotate the R A setting circle until it reads 18h36m Your are now ready to use the setting circles to find objects in the sky Finding objects using the set...

Страница 13: ...pe in mm by the magnification Exit Pupil Diameter of Primary mirror in mm Magnification For example a 200mm f 5 telescope with a 40mm eyepiece produces a magnification of 25x and an exit pupil of 8mm...

Страница 14: ...lso affects images Astronomy is an outdoor activity The best conditions will have still air and obviously a clear view of the sky It is not necessary that the sky be cloud free Often broken cloud cond...

Страница 15: ...p which covers the front of the telescope and look down the optical tube At the bottom you will see the primary mirror held in place by three clips 120 apart and at the top the small oval secondary mi...

Страница 16: ...ew there If there is you will want to loosen it turn the screw to the left to bring the mirror away from that point If there isn t a adjusting screw there then go across to the other side and tighten...

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