70900 NG - Telescope BRESSER - Free user manual and instructions

USER MANUAL 70900 NG BRESSER

Your telescope has the following parts (Figures 1–3) 1 Telescope tube 2 Finder 3 Adjusting crews for nder 4 Tube opening 5 Objective lens 6 Eyepiece holder 7 Focus adjustment knob 8 Tube holder 9 Tripod head (with pole elevator cradle and mount) 10 Accessory tray 11 Locking clips (on tripod) 12 Mounting bracket for the tray (on division bar) 13 Tripod legs 14 Flexible shaft (long) 15 Flexible shaft (short) 16 Tripod leg brace 17 Latitude control rod 18 3 Eyepices (Ø 31.7 mm or 11/4”): f = 20 mm, f = 12 mm, f = 4mm 19 Zenith mirror 20 Inverting lens 1.5x STEP I – Assembly

2. General Information regarding Assem-

bly, Positioning Before beginning with the assembly, choose a suitable position for your telescope. It will help if you assemble this apparatus at a spot from where you have a clear view of the sky, a sturdy surface beneath you, and enough space. Important: Tighten screws only as much as you can by hand - do not „over-tighten“ the screws.

Take the three-legged tripod and set it vertically on the oor with the feet pointing downwards. Now take two of the tripod legs (13) and pull these legs carefully out away from each other, until they have reached their fully opened po- sition. During this time, the entire weight of the Parts of the Eyepiece holder (Figure 8) 21 Clamping screw 21a Lens Cover Parts of the Zenith Mirror (Figure 9) 22 Clamping screw Parts of the Finder (Figure 10) 23 Front lens mount (objective lens) 23a Objective lens counter-ring 24 Finder holder Parts of the Telescope Tube (Figure 12) 25 Lens Cover Axel with exible shaft (Figure 13) 26,27 Clamping screw for the exible shaft Pole elevator cradle (Figure 14) 28 Clamping screw for pole elevator cradle 29 Latitude control rod 30 Tilt plate Parts of the Mount (Figure 15) 26 Flexible shaft (for counterweight shaft, for tracking) 27 Flexible shaft (for declination shaft) 31 Vertical clamp 31a Declination shaft 32 Dovetail adapter 33 Horizontal clamp

tripod rests on one leg. Finally, set the tripod down on all legs, so that it stands straight. Loosen the three locking clips (11) (Figure 1 + 4) on the tripod legs, pull each individual tripod leg out until it has reached the desired length (see gure 4), close up the locking clips and set the tripod down on a sturdy, even surface. TIP: A small water level on the accessory tray can help you position your tripod horizontally.

4. Mounting the tray:

The accessory tray (10) (Figure 1 + 3) must be positioned with its at side down in the midd- le of the tripod leg brace (16) (Figure 1), and then must be mounted by turning it 60° in a clockwise direction (Figure 5). The three projections on the tray plate must match up to the mounting brackets on the di- vision bars (12) (Figures 1 + 3) and must snap into place. If necessary, you may push the tri- pod leg brace downwards a little.

In order to mount the telescope tube (1) (Fig. 1), loosen the locking screw on the tube clamp (8) (Fig. 6) and open up the clamp. Set the tube in the middle of the holder and snap the clamp shut again. Please screw the locking screw on the holder tightly, using your hand only. Now set the tube (and holder) onto the mount with the objective opening in the direction marked (N-marking on the tripod head, nor- th point and telescope gure on the mount). Then fasten the tube holder with the clamping screw of the dovetail adapter on the mount head (Figure 7).

6. Inserting the Eyepiece

Three eyepieces (18) (Figure 2) and one ze- nith mirror (19) (Figure 2) come with your te- lescope. With the eyepieces, you can control the magnication of your telescope. Before installing the eyepieces and the zenith mirror, take the lens cap (21a) out of the eye- piece holder (6) (Figure 1). Loosen the clam- ping screws (21) on the eyepiece holder and insert the zenith mirror. Then screw the clamp screws (21) back on.

On the nder holder, there are adjusting screws for the nder (3) (Figure 1): two clamp screws (black) and one spring-loaded counter screw (silver). The clamp screws (black) are to be screwed (equally as far) in so that you can feel some resistance; the nderscope is then secure. Before beginning an observation, it is abso- lutely necessary that you align the ndersco- pe – the nderscope and the main telescope must point to exactly the same position. Here is the process for alignment: Take the 20-mm eyepiece, set it into the ze- nith mirror and aim the main telescope at an easy to nd, clearly dened earthbound ob- ject (Figure 11, e.g. church steeple, gable of a house). The object should be at least 200- 300 meters away. Hone in on the object so that it is exactly in the middle of the eld of vision when you look through the eyepiece. The image reproduced will be upright, but rotated around its vertical axis (you will see a mirror-image). In the nder, however, the re- produced image will be upright and its sides will not be reversed, as above. Now turn one of the two clamp screws (right/left) of the n- derscope while looking continuously through the nder. Continue to turn until the nder’s crosshairs are exactly over the position that corresponds to what you see when you look through the eyepiece of the main telescope. Focusing the nderscope: Turn the front lens mount (23) one to two rotations to the left. Now you can adjust the counter-ring (23a) by itself. Finally, in the same way (by opening and clo- sing the clamp screws) secure the 20-mm eyepiece in the zenith mirror. Be sure that the entrance of the eyepiece (the end you look into) is facing straight upwards. This will make observation easier. Alterna- tively, loosen the clamp screws (21) on the eyepiece holder and turn the zenith mirror into this position.

7. Mounting and Adjusting the Finder

Slide the foot of the nder holder (24) com- pletely into the nder holder base on the te- lescope tube (Figure 10). The nder holder will snap into place. Be sure that the objective lens on the nder is pointing in the direction of the front tube opening.

In order to protect the interior of your telesco- pe from dust and dirt, the opening of the tube is protected by a lens cover. There is also a lens cover (21) on the eyepiece holder (6) (Fi- gure 1). For observing, take the caps off the open- ings. STEP II – Using the Telescope

1. Operation –Mounting

Your telescope comes with a mount that gives you two possibilities for observation. A: Azimuthal = ideal for viewing objects on the Earth (terrestrial observation) B: Parallactic = ideal for viewing objects in the sky (astronomical observation) Regarding A: In azimuthal mode, the telescope swings hori- zontally and vertically.

In order to facilitate the exact ne adjustment of the declination- and right ascension shafts, the exible shafts have been placed on the holders of both these shafts, in the places de- signed for that purpose. The long exible shaft (14) (Figure 1) is moun- ted parallel to the telescope tube. It is secured with a clamp screw (16, 17) on the designated indentation on the shaft. The short exible shaft (15) (Figure 1) is moun- ted sideways. It is secured with a clamp screw (16, 17) on the designated indentation on the shaft. Your telescope is now ready for use. Look through the nder and focus on a far- away object. Turn the front lens mount (23) in one direction or another until the object ap- pears in focus. Now screw the counter-ring (23a) in the direction of the lens mount.

the astronomical observation. Do not observe from closed spaces, and set up your telescope with the accessories approx. 30 minutes before beginning obser- vation; this will ensure that the temperatures inside the tube have adjusted. In addition, you should be careful to set your telescope on a level, stable surface.

3. First time Set-up

Loosen the pole elevator clamp screw (28) and set the tilt plate (32) roughly to the latitu- de of your location, according to the scale of the latitude control rod (29) - in Germany, this is about 50°. Point the part of the tripod with the North-marking (N) in a northerly direction. The upper side of the tilt plate will also be pointing north. The latitude control rod will be pointing south.

4. Positioning of Geographical Latitude

From a street map, an atlas, or the Internet, nd out your location’s angle of latitude. Ger- many lies between 54° (Flensburg) and 48° (Munich) north geographical latitude. Now loosen the pole elevator clamp screw (28) and tilt the tilt plate (32) until the number on the latitude control rod (29) that is next to the clamp is the same number as your location‘s angle of latitude (e.g. 51°). TIP: The angle of latitude can always be found in an atlas on the right side, or on the left side of a map. You can get more informati- on at your city hall, your land registry of- ce, or on the Internet: for instance, at www.heavens-above.com. There, under “An- onymous user > Select,” you can choose your country; the relevant information will then come up.

5. Final orientation

Turn the declination shaft (8) as well as the telescope holder upwards 90° (white arrow markings at the front of the mount will be across from each other). Set the tube the right way around (see telescope illustration and north arrow) in the holder and tighten the clamp screw. The eyepiece of the telescope is now pointing at the ground; the objective lens is pointing at the North Star. Loosen rst the clamp of the latitude control rod and then the clamp of the declination shaft, and bring the North Star into the middle of the eyepiece eld of vision. Finally, retighten the clamp. From this point onward, the tripod may not be moved or ad- justed because the orientation will be lost. Loosen the pole elevator clamp screw (28) and lower the tilt plate (30) until it is horizontal (in other words, until it stops). Screw the pole elevator clamp screw back on. Loosen the vertical clamp (31) and set the tube in a horizontal position. Screw the clamp back on.

By turning both exible shafts (14, 15) (Figure 1), the telescope can be moved horizontally and vertically. Regarding B: Kapitel (3–11).

2. Set-Up (at night)

A dark location is very important for many ob- servations, as bothersome lights (lamps, lan- terns) can have quite a negative effect on the detail and clarity of the telescope image. If you leave a bright room at night to go outside, your eyes need time to adjust to the darkness. After approx. 20 minutes, you can begin with22 TIP: Eyepieces are lens systems designed for your eye. In an eyepiece, the clear image that is ge- nerated in the focal point of a lens is captured (in other words, made visible) and magnied still more. Eyepieces with various focal widths are necessary in order to achieve various de- grees of magnication. Begin each observati- on with an eyepiece with a low magnication (= large focal width, e.g. 20 mm). The telescope is now properly oriented. This procedure is necessary for tracking celestial bodies.

6. Tracking- and/or Observation Position

Loosen the vertical clamp (8) and tilt the te- lescope tube 90° downwards. Loosen the horizontal clamp (33) and turn the telescope 180° to the right or left, until the objective lens is pointing in the direction of the sky. Retighten all clamps so that you can track with the exible shaft. The manual operation of the counterweight axis (right ascension axis, R.A. axis) via the exible shaft (26) allows for the rotation of the Earth in such a way that the positioned object always stays in the eyepiece eld of vision. If you would like to switch to another object, loosen the clamps, swing with the tube in the proposed direction and retighten the clamps. The ne adjustment is then performed with the exible shafts (14, 15) (Figures 1).

Your telescope is now roughly aligned and set up. In order to obtain a comfortable observation position, carefully loosen the screw on the tube clamp (8) (Figure 1) so that you can turn the telescope tube. Bring the eyepiece and the nderscope into a position from which you can observe comfortably. The ne adjustment happens with the help of the nderscope (2). Look through the nder and try to hone in on, for instance, the North Star (Figure 16), positioning it in the middle of the nder‘s crosshairs (Figure 17). For the ex- act adjustment, the shaft of the counterweight axis (26) as well as the shaft of the declination axis (27) will be helpful.

After you have located the North Star in the nder, you will be able to recognize the North Star when you look through the eyepiece of the telescope. If needed, you can angle the telescope even more exactly toward the star (with the help of the exible shafts), or you can adjust the focus with the focus knob (7) (Figure 1). Additionally, you can now switch to a higher magnication by changing the eyepiece (to a smaller focal width). Please be aware that the magnication of the stars is barely perceptib- le.

In the beginning, you will certainly nd it dif- cult to orient yourself in the sky, since stars and constellations are always moving, and their position in the sky varies according to the season, date, and time. The North Star is an exception to this. If you were to imagine the polar axis of the Earth ex- tending out into space, it would approximately hit the North Star. The so-called north celestial pole is the starting point for all star charts. The zenith Mirror (19) (Figure 2) produces an image reversal (mirror-image) and is only used for astronomical observation. In order to see an image that is upright and properly orientated side-to-side (no mirror- image, in other words), you must use the in- verting lens that came with your telescope. Loosen the clamping screw (39) and take the zenith mirror out of the eyepiece holder (6) (Figure 1). Then set the inverting lens (20) (Fi- gure 2) straight into the eyepiece holder and retighten the clamping screws with your hand. Then, place the eyepiece (e.g. f = 20 mm) into the opening of the inverting lens and tighten the clamping screw there. Focal width of the telescope tube : Focal width of the eyepiece = Magnication Let’s calculate: 900 mm : 20 mm = 45x 900 mm : 12 mm = 75x 900 mm : 4 mm = 225x Note: On the drawing (Figure 18), you see a num- ber of the more familiar constellations and star clusters, which are visible throughout the year. The position of the stars is, of course, depen- dent on date and time. If you have xed your telescope on one of the- se stars, you will notice that within a short time it disappears from the eyepiece eld of vision. In order to compensate for this effect, opera- te the exible shaft (17) of the counterweight axis, und your telescope will follow the appa- rent path of this star.

Three eyepieces (18) (Figure 2) come with your telescope. By switching the eyepieces, you can control the magnication of your te- lescope. 1*24

11. Dismantling the Telescope

Hopefully your observation session will have been interesting and successful; afterwards, it is recommended to store the telescope in a dry and well-ventilated room. Please do not forget to place the lens caps back onto the front tube opening and the eyepiece holder. All eyepieces and optical accessories should also be stored in their respective containers. TIP: The inverting lens is not suitable for astrono- mical observation. Here, work with just the zenith mirror and an eyepiece. For terrestrial observations and for viewing nature, you may use the inverting lens with an eyepiece. Problem Solution No image Remove lens cap from lens opening Fuzzy image Adjust focus with focus adjustment knob Focusing is not possible Wait for temperatures inside tube to balance out (about 30 minutes) Bad image Never observe through a pane of glass. Object of observation is visible in nder, but not in telescope Align nder (see chapter 7) Sluggish or stiff steering of the shafts Balance telescope Image is “askew,” even with zenith mirror The eyepiece holder in the zenith mirror must be aligned vertically Troubleshooting:25

• Double-lens system (achromatic) made of glass

• Alt-azimuth mount with equatorial wedge (Optimised mounting system with exible shafts)

• Focal Length: 900 mm

• Adjustable Aluminium Tripod

2. Possible objects for observation:

We have compiled and explained a number of very interesting celestial bodies and star clus- ters for you. On the accompanying images at the end of the instruction manual, you can see how objects will appear in good viewing conditions through your telescope using the eyepieces that came with it. The Moon The moon is the Earth’s only natural satellite. Figure 19) Diameter: 3.476 km Distance: approx. 384 401 km The moon has been known to humans since prehistoric times. It is the second brightest object in the sky (after the sun). Because the moon circles the Earth once per month, the angle between the Earth, the moon and the sun is constantly changing; one sees this change in the phases of the moon. The time between two consecutive new moon phases is about 29.5 days (709 hours). Orion Nebula (M 42) M 42 in the Orion constellation (Figure 20) Right ascension: 05:32.9 (Hours: Minutes) Declination: -05:25 (Degrees: Minutes) Distance: 1.500 light years With a distance of about 1500 light years, the Orion Nebula (Messier 42, abbreviation: M 42) is the brightest diffuse nebula in the sky – visi- ble with the naked eye, and a rewarding object for telescopes in all sizes, from the smallest eld glass to the largest earthbound observa- tories and the Hubble Space Telescope. When talking about Orion, we‘re actually re- ferring to the main part of a much larger cloud of hydrogen gas and dust, which spreads out with over 10 degrees over the half of the Orion constellation. The expanse of this enormous cloud stretches several hundred light years. Ring Nebula in Lyra constellation (M 57) M 57 in the Lyra constellation (Figure 21) Right ascension: 18:51.7 (Hours: Minutes) Declination: -+32:58 (Degrees: Minutes) Distance: 2.000 light years The famous Ring Nebula M 57 in the constel- lation of Lyra is often viewed as the prototype of a planetary nebula; it is one of the magni- cent features of the Northern Hemisphere’s summer sky. Recent studies have shown that it is probably comprised of a ring (torus) of brightly shining material that surrounds the central star (only visible with larger telesco- pes), and not of a gas structure in the form of a sphere or an ellipsis. If you were to look at26 the Ring Nebula from the side, it would look like the Dumbbell Nebula (M27). With this ob- ject, we’re looking directly at the pole of the nebula. Dumbbell Nebula in the Vulpecula (Fox) constellation (M 27) M 27 in the Fox constellation (Figure 22) Right ascension: 19:59.6 (Hours: Minutes) Declination: -+22:43 (Angle: Minutes) Distance: 1.250 light years The Dumbbell Nebula (M 27) in Fox was the rst planetary nebula ever discovered. On July 12, 1764, Charles Messier discovered this new and fascinating class of objects. We see this object almost directly from its equato- rial plane. If you could see the Dumbbell Ne- bula from one of the poles, it would probably reveal the shape of a ring, and we would see something very similar to what we know from the Ring Nebula (M 57). In reasonably good weather, we can see this object well even with small magnications. f=20 mm f=12 mm f=4 mm The Moon Orion Nebula (M 42) Ring Nebula in Lyra constellation (M 57) Dumbbell Nebula in the Vulpecula (Fox) constellation (M 27)

• 3 okulary: K-20 / K-12 / K-4 mm

• 3 ks okuláre: K-20 / K-12 / K-4 mm