Orion STARBLAST 9814 User Manual

INSTRUCTION MANUAL
IN 201 Rev. A 08/02
Providing Exceptional Consumer Optical Products Since 1975
Customer Support (800)676-1343 E-mail: support@telescope.com
Corporate Offices (831)763-7000 P.O. Box 1815, Santa Cruz, CA 95061
Orion
StarBlast
#9814 4.5" Altazimuth Reflector Tabletop Telescope
2
Figure 1.
The StarBlast.
1
2
4
5
3
7
12
8
9
11
10
6
3
StarBlast parts:
17mm Explorer II eyepiece
The eyepiece is the part of the telescope that you actu-
ally look through to see things.The focal length of the eyepiece and the telescope determines the magnifying power. Magnification is discussed in more detail in the Using Y our T elescope section.
EZ Finder II reflex sight
This is a special “finder” that helps you aim the tele-
scope and locate objects in the sky for viewing. The EZ Finder II generates a red LED “dot” that shows where your telescope is aimed.The use of the EZ Finder II is discussed in the Getting Started section.
Optical tube
This is the main component of the telescope.
Focuser
This is where the eyepiece is placed, and it is where
you focus.Details of the focuser are shown in Figure 2.
Tube clamp
This clamp connects the optical tube to the wood base.
Altitude tension adjustment knob
By tightening or loosening this knob, you can change
the amount tension in the altitude (up/down) motion of the telescope.
Mirror cell
This contains the primary mirror as well as the colli-
mation thumbscrews that are used to optically align the primary mirror. This is explained in Appendix A: Aligning the Mirrors.
Altazimuth base
This wooden base provides a stable mount for the tele-
scope. It allows you to move the telescope in altitude (up/down) and azimuth (left/right).
Carrying handle
This convenient handle built into the base allo ws you to
easily carry the StarBlast to your viewing location.The carrying handle is also a handy place to put your other hand when aiming the telescope. See Using Your Telescope for more details.
Eyepiece rack
A handy metal rack in which to store your e xtra ey epieces.
6mm Explorer II eyepiece
The higher-power eyepiece that comes with the StarBlast
Eyepieces are discussed in the Magnification section.
Rubber feet
Three feet provide support for the StarBlast and are
skid free. This allows you to place the StarBlast on smooth surfaces.
Figure 2 shows detail of the focuser
Focus Wheels
The focus wheels are used to bring objects into focus.
By turning them, you move the rack-and-pinion focuser (4) in and out.
Eyepiece securing thumbscrews
These thumbscrews are used to keep the eyepiece (1)
secure in the focuser (4).
Items not shown
Primary Mirror
The parabolic mirror at the rear of the optical tube (3)
gathers incoming light and focuses it with its parabolic shape.The primary mirror has a small center-mark that is explained in Appendix A. This center-mar k should not be removed.
Secondary Mirror
The secondary mirror is located near the opening of the
optical tube (3) and reflects the focused light from the primary mirror into the eyepiece (1).
Collimation cap
This small cap fits in the focuser and is used to aid in
aligning of the optics. This process is explained in Appendix A.
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Congratulations on your purchase of an Orion StarBlast telescope.Your new StarBlast is easy to use
and requires very little assembly.The StarBlast will giv e y ou breathtaking views of the Moon, planets , and even deep sky objects like the Orion Nebula. These instructions will help you set up and use your StarBlast telescope, please read them thoroughly.
Figure 2.
Details of the
focuser.
13
14
4
Table of Contents
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Getting Started . . . . . . . . . . . . . . . . . . . . . .4
Using Your Telescope . . . . . . . . . . . . . . . . . .6
Care and Maintenance . . . . . . . . . . . . . . . .9
Specifications . . . . . . . . . . . . . . . . . . . . . . .9
Appendix A:Aligning the Mirrors . . . . . . . . . . . . . 9
Appendix B:Cleaning the Optics . . . . . . . . . .11
Assembly
Assembly of the StarBlast is very easy.You just remove it from its packaging, place the telescope on a table or other flat sur­face and locate the follo wing accessories:
1 EZ Finder II reflex sight (2) 1 17mm Explorer II eyepiece (1) 1 6mm Explorer II eyepiece (11)
Attaching the EZ Finder II
Remove the two metal thumbnuts from the optical tube (Figure 3). Place the bracket of the EZ Finder II (2) on the tube so that the holes in the bracket slide over the two thread­ed posts on the tube. The EZ Finder should be oriented so that it appears as in Figure 1.Thread the thumbnuts back onto the posts to secure the EZ Finder II in place.
Inserting the Eyepiece
Loosen the eyepiece securing thumbscrews (14).Insert the chrome barrel of the 17mm Explorer II eyepiece (1) into the focuser (4) and secure it with the thumbscrews.You can place the 6mm Explorer II eyepiece (11) in the eyepiece rack (10) for use later.
Your telescope is now fully assembled and should resemble Figure 1. Remove the dust cap from the front of the telescope when it is in use.Replace it when you are finished observing.
Getting Started
It’s best to get a feel for the basic functions of the StarBlast dur­ing the day, before observing astronomical objects at night. This way you won’t have to orient yourself in the dark! Find a spot outdoors where you’ll have plenty of room to move the tele­scope, and where you’ll have a clear view of some object or vista that is at least 1/4 mile away. It is not cr itical that the tele­scope be exactly level, but it should be placed on something relatively flat to ensure smooth movement.
The StarBlast was designed specifically for visual observation of astronomical objects in the night sky. Like all Newtonian reflec­tor telescopes, it is not well suited for daytime terrestrial usage because the image in the eyepiece is inv erted (upside-down).
Placing the StarBlast
One of the great assets of the StarBlast is its extremely portable size. Due to its overall short height, you will find that viewing while sitting down on the ground next to the telescope is the most comfortable. If you wish to raise the telescope off the ground so that it can be used while standing or sitting in a chair, then a platform, such as a milk crate or table, can be used.
Altitude and Azimuth (Aiming the Telescope)
The StarBlast altazimuth base (5) per mits motion along two axes: altitude (up/down) and azimuth (left/right). See Figure 4. Moving the telescope up/down and right/left is the “natural”way people aim objects which makes pointing the telescope intuitive and easy.
Simply take hold of the telescope tube (Figure 5) and move it left or right so that the base rotates.Move it up or down in the same manner. Both motions can be made simultaneously and in a continuous manner for easy aiming.This way you can point to any position in the night sky, from horizon to horizon.
You may find it convenient to hold one hand near the carrying handle (9) to steady it while moving and aiming the telescope.
If you find that it is too hard to put your eye up to the eyepiece
(1), you can rotate the tube by loosening the knob on the tube clamp (5) and rotating the optical tube (3) until the focuser (4)
is in a convenient position. When aiming the telescope in altitude, you may find that the
optical tube (3) is either too hard to move or does not stay in place. Use the altitude adjustment tension knob (6) to change the amount of tension between the tube clamp (5) and the altazimuth base (8) to find the right level of tension to prop­erly move and balance the telescope.
Figure 3. The EZ Finder II securing thumbnuts.
WARNING: Never look directly at the
Sun through your telescope or its finder scope—even for an instant—without a professionally made solar filter that completely covers the front of the instrument, or permanent eye damage could result.Young children should use this telescope only with adult supervision.
5
Focusing the Telescope
With the 17mm Kellner eyepiece (1) inserted into the focuser (4) and secured with the thumbscrews, aim the opti­cal tube (3) 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 (15) 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, just to make sure you’ve hit the exact focus point.
Operating the EZ Finder II reflex finder
The EZ Finder II reflex finder (2) (Figure 6) works by project- ing a tiny red dot onto a lens mounted in the front of the unit. When you look through the EZ Finder II, the red dot will appear to float in space.The red dot is produced by a light­emitting diode (LED), not a laser beam, near the rear of the sight. A replaceable 3-volt lithium battery provides the power for the diode.
Do You Wear Eyeglasses?
If you wear eyeglasses, you may be able to keep them on while you observe.In order to do this, your eyepiece must have enough “e ye relief”to allow you to see the entire field of view with glasses on.You can try looking through the eyepiece first with your glasses on and then with them off , to see if the glasses restrict the view to only a portion of the full field. If the glasses do restrict the field of view, you may be able to observe with your glasses off by just refo­cusing the telescope to your unaided vision.
If your eyes are astigmatic, images will probably appear best with glasses on. This is because a telescope’s focuser can accommodate for nearsightedness or far­sightedness, but not astigmatism.If you have to wear your
glasses while observing
and cannot see the
entire field of view, you
may want to purchase
additional eyepieces that have longer eye
relief.
Short eye relief restricts the field of view for eyeglass wearers.
Long eye relief allows full field of view to be seen with or without eyeglasses.
Figure 4. The StarBlast has two axes of motion:altitude
(up/down) and azimuth (left/right).
Altitude
Azimuth
Figure 5. Try grasping the telescope as shown for easiest pointing.
One hand moves the telescope from the front of the tube while the other hand remains on the handle to keep the telescope steady.
Figure 6. The EZ Finder II reflex sight.
Power Knob
Azimuth
adjustment
Knob
Battery casing
Mounting bracket
Altitude adjustment Knob
6
To use the EZ Finder II, turn the power knob clockwise until you hear a “click” indicating that power has been turned on. With your eye positioned at a comfortable distance, look through the back of the reflex sight with both ey es open to see the red dot. The intensity of the dot can be adjusted by turn­ing the power knob.For best results when stargazing, use the dimmest possible setting that allows you to see the dot with­out difficulty.Typically, a dim setting is used under dark skies and a bright setting is used under light-polluted skies or in daylight.
At the end of your observing session, be sure to turn the power knob counterclockwise until it clicks off.When the two white dots on the EZ Finder II’s rail and power knob are lined up, the EZ Finder II is turned off.
Aligning the EZ Finder II
When the EZ Finder II is properly aligned with the telescope, an object that is centered on the EZ Finder II’s red dot should also appear in the center of the field of view 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 at least 1/4 mile away, such as a telephone pole or chimney and center it in the telescope’s eyepiece. Now, turn the EZ Finder II on and look through it. The object will appear in the field of view near the red dot.
Note: Remember that the image in the eyepiece of the StarBlast will be upside-down (rotated 180°).This is nor­mal for Newtonian reflector telescopes.
Without moving the telescope, use the EZ Finder II’s azimuth (left/right) and altitude (up/down) adjustment knobs to position the red dot on the object in the eyepiece.
When the red dot is centered on the distant object, check to make sure that the object is still centered in the telescope’s field of view. If not, recenter it and adjust the EZ Finder II’s alignment again.When the object is centered in the eyepiece and on the red dot, the EZ Finder II is properly aligned with the telescope. Figure 7 shows how the view through the EZ Finder may look while you are aligning it.
Once aligned, EZ Finder II will usually hold its alignment even after being removed and remounted.Otherwise, only minimal realignment will be needed.
Replacing the EZ Finder II Battery
Replacement 3-volt lithium batteries for the EZ Finder II are available from many retail outlets. Remove the old battery by inserting a small flat-head screwdriver into the slot on the bat­tery casing (Figure 6) and gently prying open the case. Then carefully pull back on the retaining clip and remove the old battery.Do not overbend the retaining clip. Slide the new bat­tery under the battery lead with the positive (+) side facing down and replace the battery casing.
Using your telescope
Choosing an Observing Site
When selecting a location for observing, get as far away as possible from direct artificial 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 between the indoor and outdoor air will cause image blurring and distortion.
If at all possible, escape the light-polluted city sky and head for darker country skies.You’ll be amazed at how many more stars and deep-sky objects are visible in a dark sky!
Light Pollution
Most of us live where city lights interfere with our view of the heavens.As our metropolitan areas have become more developed, the scourge of light pollution has spread, washing out many stars and nonstellar celestial objects from our sight. Faint deep sky objects become difficult or impossible to see through the murk of light pol­lution. Even bright nebulas like the Orion and Lagoon Nebulas lose much of their delicate detail.The Moon and planets are not affected;they require steady air more than dark skies, so they remain good targets for city­dwelling observers.
The International Dark-Sky Association is waging the fight against light pollution.The IDSA was founded in 1988 with the mission of educating the public about the adverse impact that light pollution has on the night sky and astronomy.Through educational and scientific means, the nonprofit IDA works to raise awareness about the problem and about measures that can be taken to solve it.
Do you need help dealing with local officials to control street or building lighting in your area? The IDA’s exten­sive support materials can show you how. Help preserve dark skies, join the IDA today! For information, write to IDA, 3225 N.First Ave., Tuscon, AZ 85719-2103 or visit their website: www.darksky.org.
The best way to avoid immediate problems with light pol­lution, however, is to take you telescope to where there are dark skies.You will be amazed at how many stars you can see when you get away from the city lights.
Figure 7. The
EZ Finder II superimposes a tiny red dot on the sky, showing right where the telescope is pointed.
7
“Seeing” and Transparency
Atmospheric conditions vary significantly from night to night. “Seeing” refers to the steadiness of the Earth’s atmosphere at a given time.In conditions of poor seeing, atmospheric turbu­lence causes objects viewed through the telescope to “boil”. If, when you look up at the sky with your nak ed e yes, the stars are twinkling noticeably, the seeing is bad and you will be lim­ited to viewing with low powers (bad seeing affects images at high powers more sev erely).Planetary observing may also be poor.
In conditions of good seeing, star twinkling is minimal and images appear steady in the eyepiece. Seeing is best over­head, worst at the horizon. Also, seeing generally gets better after midnight, when much of the heat absorbed by the Earth during the day has radiated off into space.
Especially important for observing faint objects is good “trans­parency” - air free of moisture, smoke, and dust. All tend to scatter light, which reduces an object’s brightness. Transparency is judged by the magnitude of the faintest stars you can see with the unaided eye (6th magnitude or fainter is desirable).
If you cannot see stars of magnitude 3.5 or dimmer then con­ditions are poor.Magnitude is a measure of how bright a star is - the brighter a star is, the lower its magnitude will be. A good star to remember for this is Megrez (mag.3.4), which is the star in the “Big Dipper” connecting the handle to the “dip­per”. If you cannot see Megrez, then you have fog, haze, clouds, smog, or other conditions that are hindering your viewing.(See Figure 8)
Tracking Celestial Objects
The Earth is constantly rotating about its polar axis, complet­ing one full rotation every 24 hours; this is what defines a “day”.We do not feel the Earth rotating, but we see it at night from the apparent movement of stars from east to west.
When you observe any astronomical object, you are watching a moving target.This means the telescope’s position must be continuously adjusted over time to keep an object in the field of view. This is easy to do with the StarBlast because of its smooth motions on both axes. As the object moves off
towards the edge of the field of view, just lightly nudge the tel­escope to re-center it.
Objects appear to move across the field of view f aster 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 StarBlast.Your telescope comes with two Kellner eyepieces (Figure 9): a 17mm, which gives a magnification of 26x, and a 6mm, which gives a magnification of 75x. Other eyepieces can be used to achieve higher or lower powers. It is quite common for an observer to own five or more eyepieces to access a wide range of magnifications.
To calculate the magnification of a telescope-eyepiece combi­nation, simply divide the focal length of the telescope by the focal length of the eyepiece.
Telescope Focal Length (mm) ÷ Eyepiece Focal
Length(mm) = Magnification
For example, the StarBlast, which has a focal length of 450mm, used in combination with the 17mm eyepiece, yields a magnification of
450mm ÷ 17mm = 26x
Whatever you choose to view, always start by inserting your lowest-power (longest focal length) eyepiece to locate and center the object. Low magnification yields a wide field of view, which shows a larger area of sky in the eyepiece.This makes finding and centering an object much easier.Trying to find and center objects with a high power (narrow field of view) eyepiece is like trying to find a needle in a haystack!
Once you’ve centered the object in the eyepiece, you can switch to a higher magnification (shorter focal length) eye-
Figure 8. Megrez connects the Big Dipper’s handle to it's “pan”.
It is a good guide to how conditions are. If you can not see Megrez (a 3.4 mag star) then conditions are poor.
Figure 9. The 17mm and 6mm Explorer II eyepieces.
1.9
4.9
2.4
1.9
2.4
1.7
3.4
2.5
8
piece, if you wish.This is recommended for small and bright objects, like planets and double stars.The Moon also takes higher magnifications well.
The best rule of thumb with eyepiece selection is to start with a low power, wide-field eyepiece, and then work your way up in magnification. If the object looks better, try an even higher magnification eyepiece. If the object looks worse, then back off the magnification a little by using a lower-power eyepiece.
What to Expect
So what will you see with your telescope? You should be able to see bands on Jupiter, the rings of Saturn, craters on the Moon, the waxing and waning of Venus, and many bright deep-sky objects. Do not expect to see color as you do in NASA photos, since those are taken with long-exposure cam­eras and have “false color” added. Our eyes are not sensitive enough to see color in deep-sky objects except in a fe w of the brightest ones.
Remember that you are seeing these objects using your own telescope with your own eyes! The object you see in your e y e­piece is in real-time, and not some conveniently provided image from an expensive space probe. Each session with your telescope will be a learning experience. Each time you work with your telescope it will get easier to use, and stellar objects will become easier to find.Take it from us, there is big difference between looking at a well-made full-color NASA image of a deep-sky object in a lit room during the daytime, and seeing that same object in your telescope at night. One can merely be a pretty image someone gave to you.The other is an experience you will never forget!
Objects to Observe
Now that you are all set up and ready to go, one critical deci­sion must be made: what to look at?
The Moon
With its rocky surface, the Moon is one of the easiest and most interesting targets to view with your telescope. Lunar
craters, marias, and even mountain ranges can all be clearly seen from a distance of 238,000 miles away! With its ever­changing phases, you’ll get a new view of the Moon every night.The best time to observe our one and only natural satel­lite is during a partial phase, that is, when the Moon is NOT full. During partial phases, shadows are cast on the surface, which reveal more detail, especially right along the border between the dark and light portions of the disk (called the “ter­minator”). A full Moon is too bright and devoid of surface shadows to yield a pleasing view. Make sure to observe the Moon when it is well above the horizon to get the sharpest images.
Use an optional Moon filter to dim the Moon when it is very bright. It simply threads onto the bottom of the eyepieces (you must first remove the eyepiece from the focuser to attach a fil­ter).You’ll find that the Moon filter improves viewing comfort, and also helps to bring out subtle features on the lunar sur­face.
B.The Sun
You can change your nighttime telescope into a daytime Sun viewer by installing an optional full-aperture solar filter over the front opening of the StarBlast. The pr imary attraction is sunspots, which change shape, appearance, and location daily. Sunspots are directly related to magnetic activity in the Sun. Many observers like to make drawings of sunspots to monitor how the Sun is changing from day to day.
Important Note: Do not look at the Sun with any optical instrument without a professionally made solar filter, or permanent eye damage could result. Do not use the EZ Finder when solar viewing either .
C.The Planets
Planets, being in our own solar system and having their own orbits, do not stay at “fixed” locations like the stars do.So to find them you should refer to Sky Calendar at our website (tel­escope.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 StarBlast 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, optional higher-power eyepieces are recom­mended and often needed for detailed observations. Not all the planets are generally visible at any one time.
JUPITER: The largest planet, Jupiter, is a great subject for observation. You can see the disk of the giant planet and watch the ever-changing positions of its four largest moons ­Io, Callisto, Europa, and Ganymede.
SATURN:The ringed planet is a breathtaking sight when it is well positioned.The tilt angle of the rings varies over a period of many years; sometimes they are seen edge-on, while at other times they are broadside and look like giant “ears” on each side of Saturn’s disk. A steady atmosphere (good see­ing) is necessary for a good view. You will probably see a bright “star” close by, which is Saturn’s brightest moon, Titan.
VENUS: At its brightest, Venus is the most luminous object in the sky, excluding the Sun and the Moon. It is so bright that
Magnification Limits
Every telescope has a useful magnification limit of about 2X per millimeter of aperture. This comes to 226X for the StarBlast. Some telescope manufacturers will use mis­leading claims of excess magnification, such as “See distant galaxies at 640X!”. While such magnifications are technically possible, the actual image at that magnifica­tion would be an indistinct blur.
Moderate magnifications are what give the best views.It is better to view a small, but bright and detailed image than a dim, unclear, oversized image.
9
sometimes it is visible to the naked eye during full daylight! Ironically, Venus appears as a thin crescent, not a full disk, when at its peak brightness.Because it is so close to the Sun, it never wanders too far from the morning or evening horizon. No surface markings can be seen on Venus, which is always shrouded in dense clouds.
D.The Stars
Stars will appear like twinkling points of light. Even powerful telescopes cannot magnify stars to appear as more than a point of light.You can, however, enjoy the different colors of the stars and locate many pretty double and multiple stars. The gorgeous two-color double star Albireo in Cygnus is a fav orites.Defocusing a star slightly can help bring out its color.
E. Deep-Sky Objects
Under dark skies, you can observe a wealth of fascinating deep-sky objects, including gaseous nebulas, open and glob­ular star clusters, and a variety of different types of galaxies. Most deep-sky objects are very faint, so it is important that you find an observing site well away from light pollution.Take plenty of time to let your eyes adjust to the darkness.Do not expect these subjects to appear like the photographs you see in books and magazines; most will look like dim gray smudges. Our eyes are not sensitive enough to see color in deep-sky objects except in a few of the brightest ones. But as you become more experienced and your observing skills get sharper, you will be able to ferret out more and more subtle details and structure.
To find deep sky objects in the sky, it is best to consult a star chart or Planisphere. These guides will help you locate the brightest and best deep-sky objects for viewing with your StarBlast .
You can also try low-power scanning of the Milky W a y. Use the 17mm eyepiece and just cruise through the “star clouds” of our galaxy. You’ll be amazed at the rich fields of stars and objects you’ll see! The Milky Wa y is best observed on summer and winter evenings.
Care and Maintenance
If you give your telescope reasonable care, it will last a life­time. Store it in a clean, dry, dust-free place, safe from rapid temperature changes and humidity .Do not store the telescope outdoors, although storage in a garage or shed is OK. Small components like eyepiece and other accessories should be kept in a protective box or storage case. Keep the dust caps on the front of the scope and on the focuser when it is not in use.
The telescope requires very little mechanical maintenance. The optical tube is made of steel and has a smooth painted finish that is fairly scratch resistant. If a scratch does appear on the tube, it will not harm the telescope. Smudges on the tube can be wiped off with e soft cloth and a household clean­er such as Windex or Formula 409.
Refer to Appendix B for detailed instructions on how to clean the optics of the StarBlast.
Specifications
Primary mirror: Parabolic, center marked Primary mirror diameter: 113mm Secondary mirror minor axis: 34.3mm Mirror coatings: Aluminum with Si
O
2
overcoat Focal length:450mm Focal ratio:f/4.0 Focuser: Rack-and-pinion, accepts 1.25" eyepieces Eyepieces:17mm and 6mm Explorer II, 1.25" Magnification: 26x (with 17mm), 75x (with 6mm) Finder: EZ Finder II reflex sight Mount:Altazimuth, wood base, eyepiece rac k, integ ral carry handle Weight:13 lbs. Tube Length:18" Tube Outer Diameter: 5.5"
Appendix A: Aligning the Mirrors
Your telescope’s optics were aligned at the factory , and should not need much adjustment unless the telescope is handled roughly. Accurate mirror alignment is impor tant to ensure the peak performance of your telescope, so it should be checked regularly .Collimating (aligning the mirrors) is relatively easy to do and can be done in daylight.
To check collimation (mirror alignment), remove the eyepiece and look down the focuser (4) .You should see the secondary mirror (16) centered in the drawtube, as well as the reflection of the primary mirror (15) centered in the secondar y mirror, and the reflection of the secondary mirror (and your eye) cen­tered in the reflection of the primary mirror, as in Figure 10a.If anything is off-center, as in Figure 10b, proceed with the fol­lowing collimation procedure.
The Collimation Cap and Mirror Center Mark
Your StarBlast comes with a collimation cap (17). This is a simple cap that fits on the focuser like a dust cap, but has a hole in the center and a silver bottom.This helps center your eye so that collimating is easy to perform. Figures 10b, c, d and e assume you have the collimation cap in place.
In addition to the collimation cap, the primary mirror is marked with a ring with the hole exactly at the center of the primary mirror.This is of great help in collimating the primary mirror since you can center the dot of the collimation cap in the mid­dle of the ring.
Note:The center ring sticker need not ever be removed from the primary mirror. Because it lies directly in the shadow of the secondary mirror, its presence in no way adversely affects the optical performance of the tele­scope or the image quality. That might seem counterintuitive, but it’s true!
10
Aligning the Secondary Mirror
With the collimation cap in place, look through the hole in the cap at the secondary (diagonal) mirror. Ignore the reflections for the time being.The secondary mirror itself should be cen­tered in the focuser drawtube, in the direction parallel to the length of the telescope. If it isn’t, as in Figure 10b, it must be adjusted.This adjustment will rarely, if ever need to be done.
It helps to adjust the secondary mirror in a brightly lit room with the telescope pointed towards a bright surface, such as white
paper or wall. Also placing a piece of white paper in the tele­scope tube opposite the focuser (in other words, on the other side of the secondary mirror) will also be helpful in collimating the secondary mirror. Using a 2mm hex key, loosen the three small alignment set screws in the center hub of the 4-vaned spider several turns.Now hold the secondary mirror holder sta­tionary (be careful not to touch the surface of the secondary mirror), while turning the center screw with a Phillips head screwdriver (See Figure 11).Turning the screw clockwise will move the secondary mirror toward the front opening of the optical tube, while turning the screw counter-clockwise will move the secondary mirror toward the primary mirror.
Note:When making these adjustments, be careful not to stress the spider vanes or they may bend.
When the secondary mirror is centered in the focuser draw­tube, rotate the secondary mirror holder until the reflection of the primary mirror is as centered in the secondar y mirror as possible.It may not be perfectly centered, but that is OK. Now tighten the three small alignment screws equally to secure the secondary mirror in that position.
If the entire primary mirror reflection is not visible in the sec­ondary mirror, as in Figure 10c; you will need to adjust the tilt of the secondary mirror.This is done by alternately loosening one of the three alignment set screws while tightening the other two, as depicted in Figure 12.The goal is to center the primary mirror reflection in the secondar y mirror, as in figure 10d. Don’t worry that the reflection of the secondar y mirror (the smallest circle, with the collimation cap “dot” in the cen­ter) is off-center.You will fix that in the next step.
a.
b.
c.
d.
e.
Figure 10. Collimating the optics.(a) When the mirrors
are properly aligned, the view down the focuser drawtube should look like this.(b) With the collimation cap in place, if the optics are out of alignment, the view might look something like this.(c) Here, the secondary mirror is centered under the focuser, but it needs to be adjusted (tilted) so that the entire primary mirror is visible. (d) The secondary mirror is correctly aligned, but the primary mirror still needs adjustment.When the primary mirror is correctly aligned, the “dot” will be centered, as in (e).
Figure 12.
Adjust the tilt of the secondary mirror by loosening or tightening the three alignment set screws with a 2mm hex key.
Alignment set screws (3)
Figure 11. To
center the secondary mirror under the focuser, hold the secondary mirror holder in place with your fingers while adjusting the center screw with the Phillips head screwdriver.Do not touch the mirror’s surface.
11
Aligning the Primary Mirror
The final adjustment is made to the primary mirror.It will need adjustment if, as in Figure 10d, the secondary mirror is cen­tered under the focuser and the reflection of the primary mirror is centered in the secondary mirror, but the small reflec­tion of the secondary mirror (with the “dot” of the collimation cap) is off-center.
The tilt of the primary mirror is adjusted with three spring­loaded collimation thumbscrews on the back end of the optical tube (bottom of the primary mirror cell); these are the wide thumbscrews.The other three thin thumbscrews lock the mir­ror’s position in place; these thin thumbscrews must be loosened before any collimation adjustments can be made to the primary mirror.
To start, turn the thin thumbscrews that lock the primary mir­ror in place a few turns each.(Figure 13)
Now, try tightening or loosening one of the wide collimation thumbscrews with your fingers (Figure 14). Look into the focuser and see if the secondary mirror reflection has moved closer to the center of the primary. You can tell this easily with the collimation cap and mirror center mark by simply watching to see if the “dot”of the collimation cap is moving closer or fur­ther away from being centered in the “ring” of the primary mirror mark. When you have that dot centered as much as is possible in the ring, your primary mirror is collimated.The view through the collimation cap should resemble Figure 10e.Re­tighten the locking thumbscrews.
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 accurate­ly center it in the eyepiece’s field of view. Slowly de-focus the image with the focusing knob.If the telescope is correctly colli­mated, the expanding disk should be a perfect circle (Figure 15). If the image is unsymmetrical, the scope is out of collimation.The dark shadow cast by the secondary mirror should appear in the very center of the out-of-focus circle, like the hole in a donut.If the “hole”appears off-center, the telescope is out of collimation.
If you try the star test and the bright star you have selected is not accurately centered in the eyepiece, the optics will always appear out of collimation, even though they may be perfectly aligned. It is critical to keep the star centered, so over time you will need to make slight corrections to the telescope’s position in order to account for the sky’ s apparent motion.
Appendix B: Cleaning the Optics
Cleaning Lenses
Any quality optical lens cleaning tissue and optical lens clean­ing fluid specifically designed for multi-coated optics can be used to clean the exposed lenses of your eyepieces. Never use regular glass cleaner or cleaning fluid designed for eye­glasses
Before cleaning with fluid and tissue, blow any loose particles off the lens with a blower bulb or compressed air.Then apply some cleaning fluid to a tissue, never directly on the optics. Wipe the lens gently in a circular motion, then remove any excess fluid with a fresh lens tissue. Oily fingerprints and smudges may be removed using this method. Use caution; rubbing too hard may scratch the lens.Never reuse tissues.
Cleaning Mirrors
You should not have to clean the telescope’s mirror very often; normally once every year or so.Covering the telescope with the dust cap when it is not in use will help prevent dust from accumulating on the mirrors. Improper cleaning can scratch mirror coatings, so the fewer times you have to clean the mir­rors, the better.Small specks of dust or flecks of paint have virtually no effect on the visual performance of the telescope
The large primary mirror and the elliptical secondar y mirror of your telescope are front-surface aluminized and over coated with hard silicon dioxide, which prevents the aluminum from
Figure 13.
The three thin thumbscrews that lock the primary mirror in place must first be loosened before any adjustments can be made.
Figure 14.
The tilt of the primary mirror is adjusted by turning one or more of the three wide collimation thumbscrews.
Figure 15. A
star test will determine if the telescope's optics are properly collimated. An
unfocused view of a bright star through the eyepiece should appear as illustrated on the right if optics are perfectly collimated. If the circle is unsymmetrical, as illustrated on the left, the scope needs collimation.
Out of collimation Collimated
12
oxidizing.These coatings normally last through many years of use before requiring re-coating, which is easily done.
To clean the secondary mirror, it must be removed from the telescope.Do this by holding the secondary mirror holder sta­tionary with your fingers (dont touch the mirror itself) while unthreading the Phillips head screw in the center hub of the 4­vaned spider. Completely unthread the screw from the holder, and the holder will come loose in your fingers.Be careful not to lose the spring on the Phillips head screw.
Handle the mirror and its holder carefully.You do not need to remove the secondary mirror from its holder for cleaning. Follow the same procedure described below for cleaning the primary mirror.
To clean the primary mirror, carefully remove the mirror cell from the telescope. To do this, you must remove the three screws that connect the mirror cell to the steel tube. These screws are located on the outer edge of the mirror cell.
Now , remo ve the three mirror clips that secure the mirror in its cell;use a Phillips head screwdriver to unthread the mirror clip
anchor screws.Next, hold the mirror by its edge, and remove it from the mirror cell. Be careful not to touch the aluminized surface of the mirror with your fingers. Set the mirror on a clean, soft towel. Fill a clean sink, free of abrasive cleanser, with room-temperature water, a few drops of liquid dishwash­ing detergent, and if possible, a cap-full of rubbing alcohol. Submerge the mirror (aluminized face up) in the water and let it soak for several minutes (or hours if it is a very dirty mirror). Wipe the mirror underwater with clean cotton balls, using extremely light pressure and stroking in straight lines across the surface. Use one ball for each wipe across the mirror. Then rinse the mirror under a stream of lukewarm water. Any particles on the surface can be swabbed gently with a series of clean cotton balls, each used just one time. Dry the mirror in a stream of air (a blower bulbworks great), or remove any stray drops of water with the corner of a paper towel.Dry the bottom and the edges with a towel (not the mirror surface!). Leave the entire assembly in a warm area until it is complete­ly dry before reassembling the telescope.
One-Year Limited Warranty
This Orion StarBlast is warranted against defects in materials or workmanship for a period of one year from the date of purchase.This warranty is for the benefit of the original retail pur­chaser only.During this warranty period Orion Telescopes & Binoculars will repair or replace, at Orions option, any warranted instrument that proves to be defective, provided it is returned postage paid to: Orion Warranty Repair, 89 Hangar Way, Watsonville, CA 95076. If the product is not registered, proof of purchase (such as a copy of the original invoice) is required.
This warranty does not apply if, in Orion’s judgment, the instrument has been abused, mishan- dled, or modified, nor does it apply to normal wear and tear.This warranty gives you specific legal rights, and you may also ha ve other rights, which vary from state to state.For further war­ranty service information, contact: Customer Service Department, Orion Telescopes & Binoculars, P.O.Box 1815, Santa Cruz, CA 95061; (800)676-1343.
Orion Telescopes & Binoculars
Post Office Box 1815, Santa Cruz, CA 95061
Customer Support Help Line (800)676-1343 • Day or Evening
Loading...