BRESSER 8843205 76-300 Compact Telescope Instruction Manual

: June 4, 2024
: BRESSER

Table of Contents

BRESSER 8843205 76-300 Compact Telescope
General Warnings
Your telescope consists of these parts
Pointing your telescope
Which eyepiece is right?
Possible objects for observation
Telescope ABC’s
Technical data
Notes on cleaning
Warranty and Service
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

BRESSER 8843205 76-300 Compact Telescope

General Warnings

Risk of blindness — Never use this device to look directly at the sun or in the direct proximity of the sun. Doing so may result in a risk of blindness.
Choking hazard — Children should only use the device under adult supervision. Keep packaging material, like plastic bags and rubber bands, out of the reach of children, as these materials pose a choking hazard.
Risk of fire — Do not place the device, particularly the lenses, in direct sunlight. The concentration of light could cause a fire.
Do not disassemble the device. In the event of a defect, please contact your dealer. The dealer will contact the Service Centre and can send the device in to be repaired, if necessary.
Do not expose the device to high temperatures.
The device is intended only for private use. Please heed the privacy of other people. Do not use this device to look into apartments, for example.

Your telescope consists of these parts

BRESSER-8843205-76-300-Compact-Telescope-FIG-1

Focus wheel
Telescope (Telescope tube)
Compass
Alt-azimuth mount
Azimut scale
Scale with 90° steps
Height adjustment wheel
Eyepieces (6mm, 20mm)
Moon Filter

Please look for a suitable location for your telescope before you begin. Use a stable surface e.g. a table.

Pointing your telescope

Azimuthal mounting just means that you can move your telescope up and down, left and right. With the height adjustment wheel (7) and the turnable azimuth mount you can point the telescope at any object you want. Use the wheel (7) to tilt the telescope. By using the azimuth mount like a turntable you can pan the telescope to the left and to the right.

Which eyepiece is right?

First of all, it is important that you always choose an eyepiece with the highest focal width for the beginning of your observation. Afterwards, you can gradually move to eyepieces with smaller focal widths. The focal width is indicated in millimeters, and is written on each eyepiece. In general, the following is true: The larger the focal width of an eyepiece, the smaller the magnification! There is a simple formula for calculating the magnification:
Focal width of the telescope tube : Focal width of the eyepiece = magnification You see: The magnification is also depends on the focal width of the telescope tube. The telescope has a focal length of 300 mm. From this formula, we see that if you use an eyepiece with a focal width of 20 mm, you will get the following magnification: 300 mm / 20 mm = 15 x magnification

To make things simpler, I’ve put together a table with some magnifications:

Possible objects for observation

We have compiled and explained a number of very interesting celestial bodies and star clusters 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 13)

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 14)
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 – visible with the naked eye, and a rewarding object for telescopes in all sizes, from the smallest field glass to the largest earthbound observatories and the Hubble Space Telescope. When talking about Orion, we‘re actually referring 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 15)

Distance: 2.000 light years

The famous Ring Nebula M 57 in the constellation of Lyra is often viewed as the prototype of a planetary nebula; it is one of the magnificent 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 telescopes), and not of a gas structure in the form of a sphere or an ellipsis. If you were to look at the Ring Nebula from the side, it would look like the Dumbbell Nebula (M27). With this object, 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 16)

Distance: 1.250 light years

The Dumbbell Nebula (M 27) in Fox was the first 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 equatorial plane. If you could see the Dumbbell Nebula 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 magnifications.

Telescope ABC’s

What do the following terms mean?

Focal width:
Everything that magnifies an object via an optic (lens) has a certain focal width. The focal width is the length of the path the light travels from the surface of the lens to its focal point. The focal point is also referred to as the focus. In focus, the image is clear. In the case of a telescope, the focal widths of the telescope tube and the eyepieces are combined:

Lens:
The lens turns the light which falls on it around in such a way so that the light gives a clear image in the focal point after it has traveled a certain distance (focal width).

Eyepiece:
An eyepiece is a system made for your eye and comprised of one or more lenses. In an eyepiece, the clear image that is generated in the focal point of a lens is captured and magnified still more. There is a simple formula for calculating the magnification: Focal width of the telescope tube / Focal width of the eyepiece = Magnification
You see: In a telescope, the magnification depends on both the focal width of the telescope tube and the focal width of the eyepiece.

Magnification:
The magnification corresponds to the difference between observation with the naked eye and observation through a magnification apparatus (e.g. a telescope). In this scheme, observation with the eye is considered “single”, or 1x magnification. Accordingly, if a telescope has a magnification of 30x, then an object viewed through the telescope will appear 30 times larger than it would with the naked eye. See also “Eyepiece.“

Useful accessories can be found at www.bresser.de

Technical data

Design: achromatic
Focal length: 300 mm
Objective diameter: 76 mm

Notes on cleaning

Clean the eyepieces and lenses only with a soft, lint-free cloth, like a microfibre cloth. To avoid scratching the lenses, use only gentle pressure with the cleaning cloth.
To remove more stubborn dirt, moisten the cleaning cloth with an eyeglass-cleaning solution, and wipe the lenses gently.
Protect the device from dust and moisture. After use, particularly in high humidity, let the device acclimatise for a short period of time, so that the residual moisture can dissipate before storing.

DISPOSAL
Dispose of the packaging materials properly, according to their type, such as paper or cardboard. Contact your local waste-disposal service or environmental authority for information on the proper disposal.

Please take the current legal regulations into account when disposing of your device. You can get more information on the proper disposal from your local waste-disposal service or environmental authority.

EC Declaration of Conformity
Bresser GmbH has issued a “Declaration of Conformity” in accordance with applicable guidelines and corresponding standards. The full text of the EU declaration of conformity is available at the following internet address: www.bresser.de/download/8843205/CE/8843205_CE.pdf

Warranty and Service

The regular guarantee period is 5 years and begins on the day of purchase. You can consult the full guarantee terms and details of our services at www.bresser.de/warranty_terms.