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5

Both the altitude and azimuth axes of the SkyScanner BL are 
equipped with tension adjustment knobs, which you installed 
earlier. These should be adjusted so there is sufficient friction 
of motion to keep the telescope from rotating too freely in each 
axis, which can make it difficult to land on and stay aimed at 
an object you wish to view. However, if you apply too much 
tension the telescope will be difficult to move smoothly and in 
small increments needed to center an object in the eyepiece 
for viewing. 

Focusing the Telescope 

Both SkyScanner BL telescopes come equipped with a rack-
and-pinion focuser. The SkyScanner BL 102mm has a 1.25" 
focuser, which accepts only eyepieces with 1.25"-diameter 
barrels. The SkyScanner BL 135mm model comes with a 2" 
focuser that has a 1.25" adapter installed in it. This focuser can 
accept eyepieces with either 2"-diameter barrels or 1.25" barrels. 
To use an optional 2" eyepiece in the SkyScanner BL 135mm, 
you must first remove the 1.25" adapter from the focuser (

Figure 

22

). To do so, just loosen the thumbscrew until it is nearly all 

the way out, then the adapter can be removed. Place the 2" 
eyepiece’s barrel into the drawtube collar and tighten it with the 
thumbscrew. 

We recommend practicing focusing in the daytime when starting 
out to get the hang of it. With the 25mm eyepiece inserted into 
the focuser and secured with the thumbscrew, aim the optical 
tube so the front (open) end is pointing in the general direction 
of an object at least 1/4-mile away. With your fingers, slowly 
rotate one of the focus wheels until the object comes into sharp 
focus. Go a little bit beyond sharp focus until the image starts to 
blur again, then reverse the rotation of the knob gradually, until 
you’ve nailed the exact focus point.

Aligning and Using the Red Dot Finder Scope

The included red dot finder scope (

Figure 9

) makes pointing 

your telescope almost as easy as pointing your finger. It permits 
easy object targeting prior to observation in the higher-power 
main telescope. It superimposes a red dot generated by an inter-
nal LED light on the sky, showing right where your telescope is 
pointed (

Figure 23

). 

Before you can use the red dot finder scope, you must remove 
the small tab sticking out from the battery compartment. Doing 
so will allow the pre-installed 3V CR-2032 button cell battery to 
make contact with the finder scope’s electronic circuitry to power 
the finder’s red LED illuminator. The tab can then be discarded. 
To use the red dot finder scope properly, it must be aligned with 
the main telescope. This is easiest to do during daylight hours, 
before observing at night. Follow this procedure: 

1.   First, remove the dust cover from the front of the tele-

scope. 

2.  With the 25mm eyepiece installed in the focuser, point the 

telescope at a well-defined land target (e.g., the top of a 
telephone pole) that’s at least a quarter mile away. 

3.  Center the target in the eyepiece. 

Note: 

The image in the eyepiece will appear rotated (upside 

down). This is normal for reflector telescopes.

4.   Turn on the red dot finder scope by sliding the power 

switch to ON (refer to 

Figure 9B

). The power switch actu-

ally has two illumination settings: the middle position 

Azimuth 

adjustment 

knob

Altitude 

adjustment 

knob

Drawtube collar

Power switch

Focuser

Figure 9. A)

 Install the red dot scope by sliding the bracket into the 

base as shown. 

B) 

The power switch has two brightness settings.

Figure 10. 

Insert an eyepiece into the focuser and secure it with 

the thumbscrew.

A

B

Summary of Contents for 52598

Page 1: ...tor Telescope is designed for easy yet eye opening explora tion of the heavens If you have never owned a telescope before we would like to welcome you to amateur astronomy Take some time to familiarize yourself with the night sky Learn to recognize the patterns of stars in the major constellations With a little practice a little patience and a reasonably dark sky away from city lights you ll find ...

Page 2: ...r with interchangeable flat and Philips bit Dust cap Dust cap Optical tube Tension knob Tension knob Eyepiece rack Bottom ground plate Top ground plate Flat washers Spring washers 25mm Kellner eyepiece 3x Barlow lens Red dot scope 10mm Plossl eyepiece Assembly screws Side brace handle Side panel Screwdriver Figure 1 Parts of the SkyScanner BL 102mm Dobsonian Warning Never look directly at the Sun ...

Page 3: ...sion knob do not overtighten Figure 8B 9 Now install the red dot finder scope by sliding the bracket into the finder base on the optical tube as shown in Figure 9 10 Finally insert the 25mm eyepiece into the focuser draw tube collar and secure it with the thumbscrew Figure 10 With your telescope now fully assembled you can skip to the section titled Getting Started SkyScanner BL 135 Included Items...

Page 4: ... optical tube as shown in Figure 9 10 Finally insert the 25mm eyepiece into the focuser draw tube collar and secure it with the thumbscrew Figure 10 Getting Started The SkyScanner BL telescopes were designed specifically for visual observation of astronomical objects in the night sky Like all Newtonian reflector telescopes they are not suited for daytime terrestrial usage because the image in the ...

Page 5: ... image starts to blur again then reverse the rotation of the knob gradually until you ve nailed the exact focus point Aligning and Using the Red Dot Finder Scope The included red dot finder scope Figure 9 makes pointing your telescope almost as easy as pointing your finger It permits easy object targeting prior to observation in the higher power main telescope It superimposes a red dot generated b...

Page 6: ...tion the red dot on the object 6 When the red dot is centered on the distant object check to make sure the object is still centered in the telescope s eyepiece If it isn t re center it then adjust the finder scope s alignment again When the object is centered in the telescope eyepiece and on the finder scope s red dot the finder scope is properly aligned with the telescope The red dot finder scope...

Page 7: ... light such as street lights porch lights and automobile headlights The glare from these lights will greatly impair your dark adapted night vision Avoid viewing over rooftops and chimneys as they often have warm air currents rising from them Similarly avoid observing from indoors through an open or closed window because the temperature difference Bottom ground plate Center bolt Front panel Figure ...

Page 8: ... the eyepiece rack as shown Figure 21 The SkyScanner BL Dobsonians have two axes of motion altitude up down and azimuth left right Figure 22 The focuser on the SkyScanner BL 135mm Dobsonian has a 1 25 adapter which can be removed by loosening the thumbscrew With the adapter removed the focuser can accept optional 2 eyepieces Figure 19 Lift the optical tube into the base resting the altitude hubs o...

Page 9: ...s CR2032 battery pull down the battery cover and remove it Figure 25 Remove the old battery and place a new CR2032 battery under the spring tab with the positive side of the battery facing the tab Figure 27 The included 3x Barlow lens is inserted between the focuser and the eyepiece as shown here Figure 28 Orient the optical tube horizontally for collimation and place a piece of white paper inside...

Page 10: ...lescope to re center it Objects appear to move across the field of view faster at higher magnifications This is because the field of view becomes narrower Eyepiece Selection By using eyepieces of different focal lengths it is possible to attain many magnifications or powers with the SkyScanner BL Your telescope comes with two 1 25 eyepieces one with 25mm focal length and one with 10mm focal length...

Page 11: ...ope com or to charts published monthly in Astronomy Sky Telescope or other astronomy magazines Venus Jupiter and Saturn are the brightest objects in the sky after the Sun and the Moon Your SkyScanner BL is capable of showing you these planets in some detail Other planets may be visible but will likely appear star like Because planets are quite small in apparent size you will need to use high power...

Page 12: ...ur website for available collimating tools Figures 29B through 29D assume that you have an optional Cheshire eyepiece or collimation cap in the focuser Primary Mirror Center Mark You may have noticed that your SkyScanner BL has a small adhesive dot in the exact center of the primary mirror This center mark allows you to achieve a very precise collimation of the primary mirror you don t have to gue...

Page 13: ... on the primary mirror your primary mirror is collimated The view through the collimation cap should resemble Figure 29D Then very lightly tighten the three lock screws so that the primary mirror stays in that position A simple star test will tell you whether the optics are accurately collimated Star Testing the Telescope When it is dark point the telescope at a bright star and accu rately center ...

Page 14: ... composite base laminated Weight assembled 10 lbs 6 5 oz Tube Length 21 5 54 6cm Tube Outer Diameter 5 7 145mm SkyScanner BL 135mm Primary mirror 135mm diameter Secondary mirror 35mm minor axis Mirror coatings Aluminum with SiO2 overcoat Central obstruction 38mm 28 1 Focal length 1100mm Focal ratio f 8 1 Focuser 2 Rack and pinion accepts 1 25 and 2 eyepieces Eyepieces 25mm Kellner and 10mm Plossl ...

Page 15: ...15 ...

Page 16: ...he original retail purchaser only During this war ranty period Orion Telescopes Binoculars will repair or replace at Orion s option any warranted instru ment that proves to be defective provided it is returned postage paid Proof of purchase such as a copy of the original receipt is required This warranty is only valid in the country of purchase This warranty does not apply if in Orion s judgment t...

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