BRESSER LS80MT Modulare Multipurpose Telescope User Manual
- June 6, 2024
- BRESSER
Table of Contents
Manual
LS80MT modular Multipurpose Telescope
Modular designed multipurpose telescope, both for observing the sun in the
H-alpha wavelength, as well as for night sky observations. Easy conversion
between the different applications with a few simple steps.
ATTENTION: To use the LS80MT telescope for observation and photography of
the night sky, the additionally available conversion kit LS80MTBP&F is
obligatory needed (item number 0551330).
Included Contents:
– LS80MT telescope with 2-lens ED APO optics, FPL-53 glass
– H-alpha unit with Pressure-Tuner
– Focuser with 10:1 reduction
– Blocking-filter B1200 or B1800.
– Please note: There is also available a version without blocking-filter, at
this version is for solar observing a additionally available blocking-filter
absolutely needed!
– Tube-ring with handle and GP-level dovetail bar
– Sol-searcher integrated inside handle
– Knurled screws for easy conversion of the telescope
– Protection caps for the H-alpha unit
– Transport case
Congratulations and thank you for purchasing the modular LS80MT telescope from
Lunt Solar Systems! Enjoy observations in different wavelengths with this
high-quality telescope. The 2-lens ED optics with FPL53 glass guaranteed a
very good image in all applications.
Safety Information:
There are inherent dangers when looking at the Sun thru any instrument. Lunt
Solar Systems has taken your safety very seriously in the design of our
systems. With safety being the highest priority we ask that you read and
understand the operation of your telescope or filter system prior to use.
Never attempt to disassemble the system in another way as described in this
manual! Do not use your system if it is in some way compromised due to
mishandling or damage. Please contact our customer service with any questions
or concerns regarding the safe use of your instrument.
Never look at the Sun with your naked eye or with a telescope that is not
specifically designed to do so. Permanent and irreversible eye damage may
result!
Never leave the solar telescope unsupervised while pointed at the Sun.
People who are not familiar with the correct operating procedures of the
system may inadvertently replace the diagonal or remove the filter itself not
being aware of the integrated safety features of each.
The Lunt Solar filter/telescopes are not interchangeable with competitor
products.
A Lunt Solar Systems solar telescope houses many optical elements that are all
pre-aligned and fixed at the factory. There are no user-serviceable parts
inside the scope. The telescope should never be taken apart, except for the
modification as described in this manual! This will not only void your
warranty leading to costly repairs, it can only serve to further damage the
instrument and compromise its safety.
Most Lunt Solar Systems filters and telescopes house a delicate optical
element referred to as an Etalon. These Etalons are suspended in the system
housing in an effort to both protect it and isolate it from outside
influences, which could de-tune the Etalon filter. Extensive research has been
done to assure the best performance of what is essentially the “heart” of the
system while protecting it from the day-to-day bumps, jarring, and vibrations
of normal use. However, the instrument should never be subjected to shock due
to being dropped. Mishandling of the filters system will cause the Etalon to
de-contact (not covered under warranty) and will render the instrument useless
until repaired.
The instrument should be stored in its original case. As with any precision
optical instrument it should be kept in as low a humidity area as possible.
With proper handling and care, the filter should last a lifetime.
Okay, let’s get started…
Note:
– During shipping some knurled screws at the tube or focuser may become loose.
Simply tighten the screws.
– Included are additionally knurled screws. The headless screws on the red
H-alpha unit can be replaced by these knurled screws to make it easier to
convert the telescope later:
For solar observing in H-alpha:
Safety First!
– Always check any telescope before use for solar observing. Do not use any
telescope or filter that appears to be damaged. Verify that all glass and
filters are in place.
– The Blocking Filter diagonal or extension tube must always be used with the
Lunt telescope or filter for solar observing.
For sun observation the complete 80mm of the telescope’s aperture is used and
the focal length is 560mm.
The etalon with the air pressure tuning provides a bandwidth of <0.7 Angstrom.
Install the LS80MT telescope with the dovetail rail on an astronomical amount.
Pull the blocking-filter diagonal slide tube out about 50mm. Put the focus
tube at about 50% of travel.
Place a ~25mm eyepiece in the focus end so you have the largest field of view
to look at. Align the telescope with the shadow cast by the telescope opening
in the direction of the tube rings. There you get quite well in the direction
of the sun. For the exact alignment, you can now use the sol-searcher
integrated in the handle of the telescope.
Look thru the eyepiece. Do you see a fuzzy red ball? If not, make sure you
have removed the dust cap from the front. After some trial and error, the Sun
should appear in the eyepiece.
Focus: It is amazing how many people walk up to a solar telescope and
take a quick look thru without ever focusing. The course focus is achieved by
moving the diagonal drawtube in and out (only B1200 or B1800).
Medium focus is achieved using the larger knobs on either side of the focuser
assembly. Fine focus is achieved with the 10:1 reduction (smaller knob). The
fine focus is often too fine for visual use but comes in very handy if you are
imaging. Focus so that the edge of the Sun is as sharp as possible.
Tuning: On the side of the scope is a large black cylinder. This cylinder
is the tuning system for the H-alpha filter. Now we will describe how to bring
656.28nm wavelength on the band. The black handle of the cylinder system has a
4 start thread attaching it to the brass cylinder body. Unscrew the black
handle completely and carefully pull the piston from the cylinder. There may
be some resistance and a faint pop as the air enters the cylinder. This is
normal. This has reset the system for your altitude. Carefully re-thread the
handle onto the body and engage the threads about one turn. While looking thru
the eyepiece gently turn the black handle onto the cylinder body. There will
be little resistance at first, but as the pressure in the cylinder builds the
resistance will increase slightly. As you turn the cylinder you should see
features come into view thru the eyepiece. Continued turning will result in
the wavelength shifting thru 656.28nm and detail will begin to disappear.
Fine-tune the cylinder for the best performance.
A few details regarding the pressure tune system. The amount of pressure being
supplied to the etalon cavity is minimal. It is the equivalent of going from
-150m below sea level to about 3,000m. Or around 0.1 Bar, there is no risk of
explosion. We are dealing with only a fraction of 1 atmosphere. When not in
use we recommend that you release the pressure by simply backing off the black
handle from the cylinder body. If the system unthreads completely, simply
thread it back on 1 turn. It is not necessary to re-set the system every time
it is used. Re-setting may only be required if the system has been sitting for
a long period of time.
Re-Focus: When you feel you have tuned effectively, re-focus the
telescope. The finer details should come into view. Try to relax the eye while
observing and let the details come to you.
Change the eyepiece: When you have a good feel for observing at lower
magnifications try to increase the magnifications in small steps. Place an
interesting artifact in the center of the field. Replace the 25mm with a 8 –
12mm eyepiece. Look thru the eyepiece and re-focus carefully. The image has
dimmed slightly due to higher magnification but the details should be easier
to see. You can push the magnification as seeing conditions allow.
Seeing conditions: Please note that seeing conditions can affect the
performance of your telescope in H- alpha wavelength. Cloud cover, wind,
humidity, and air turbulence caused by heat play a major role and can
complicate the observation of details.
Double-Stacking in H-alpha:
Double stacking is also possible with the LS80MT telescope. For this purpose,
there is the additionally available double-stack module “DSII/SFPT”, item
number 0551395. This will be simply inserted between the red H-Alpha unit and
the LS80MT focuser. Detailed mounting instruction is delivered together with
the double-stack module.
This will reduce the bandwidth to <0.5 Angstroms. This significantly increases
the contrast on the surface of the sun, which makes much more details visible
on the solar surface.
For night sky observing without H-alpha unit:
Please note that for night sky observing the additionally available
conversion kit LS80MTBP&F is obligatorily needed (item number 0551330).
Loosen the 3 knurled screws between the red H-Alpha Unit and the telescope
tube. Now you can remove the H-Alpha unit together with the focuser from the
telescope.
Now the new focuser of the conversion kit can be attached to the telescope. Detailed instructions for installing are delivered with the conversion kit.
After conversion, the LS80MT can be used as a full doublet ED APO for normal night sky observation, with 80mm aperture and 560mm focal length.
Inside the transport case, you will find protection caps for the H-Alpha unit. Now attach these protection caps to the H-Alpha unit to protect it from dust and damage.
In this version without an H-alpha unit the telescope can also be used for
observing the sun in white light together with a Herschel-wedge, or together
with a LUNT Ca-K module for observing the sun in the Ca-K wavelength:
Cleaning
As with most telescopes and equipment, there will be a build-up of dust and
debris on the lens and mechanical components after sitting out all day. For
those who are familiar with cleaning telescopes we recommend you use the same
techniques. For those who are new to the care of these instruments we can
offer the following guidelines:
Blow off loose dust and dirt using a clean dry air source at low volume. Do
not use shop compressed air, which contains oil and will further contaminate
the instrument. Stubborn particulates can be brushed from the surface with a
static-free lens brush. Use gentle sweeping motions. Fingerprints and smudges
can be removed using lens tissue or a Kleenex-type tissue product. Fold the
tissue or cloth to make a “pad”, apply a cleaning product to the end of the
pad dampening it evenly (do not apply the solution to the lens), wipe in a
circular motion starting at the center and working around the edge and off in
one complete motion. Be firm, but do not rub. Blow lightly to help remove
residual solution before it “spots” the surface. Residual dust from the cloth
can be blown off.
Consult your local dealer or call Lunt Solar Systems with any questions or
concerns. Do not use Acetone or strong degreaser-type products, household
cleaning agents, paper towels, tissues with added scent or color (plain
tissues only), or bleach or acidic products that will damage the anodized
surfaces.
What can be observed on the sun in H-alpha?
The Sun is active on a daily basis. During solar maximum, the Sun will put on
awe-inspiring displays that include x-class flares, prominences, surface
filaments, etc… Prominences: These look like eruptions from the disk (edge) of
the Sun. Prominences can be small spiky-looking details or large cloud-like
detail with fine feather-like internal features. They are, in fact, ionized
hydrogen emissions being projected from the limb. Prominences are anchored to
the Sun’s surface in the mesosphere and extend outwards into the Sun’s
troposphere.
Filaments: These are string-like features on the surface of the Sun. At
high resolution, they take on a 3D effect due to the cooler aspect of the
filament contrasted against the bright, hotter, Sun. They are actually
prominences being viewed against the surface.
Spicules: A spicule is a dynamic jet of about 500km diameter on the Sun. It
moves upwards at about 20 km/s from the photosphere. Father Angelo Secchi of
the Vatican Observatory in Rome discovered them in 1877. The chromosphere is
entirely composed of spicules. These features can be seen as “fur” around the
edge of the disk.
Plage: This is a bright region in the chromosphere of the Sun, typically
found in regions of the chromosphere near sunspots. The plage regions map
closely to the faculae in the photosphere below, but the latter has much
smaller spatial scales. Faculae have a strong influence on the solar constant,
and they are more readily detectable because chromospheric plage areas
traditionally are used to monitor this influence.
Solar Flares: A solar flare is a violent explosion in the Sun’s
atmosphere. Solar flares take place in the solar corona and chromospheres,
heating plasma to tens of millions of Kelvin and accelerating electrons,
protons, and heavier ions to near the speed of light. They produce
electromagnetic radiation across the electromagnetic spectrum at all
wavelengths from long-wave radio to the shortest wavelength gamma rays. Most
flares occur in active regions around sunspots, where intense magnetic fields
emerge from the Sun’s surface into the corona. Flares are powered by the
sudden (timescales of minutes to tens of minutes) release of magnetic energy
stored in the corona.
Chromosphere: The chromosphere is a thin layer of the Sun’s atmosphere
just above the photosphere, roughly 10,000 kilometers deep (approximating to,
if a little less than, the diameter of the Earth). The chromosphere is more
visually transparent than the photosphere. The name comes from the fact that
it has a reddish color, as the visual spectrum of the chromosphere is
dominated by the deep red H-alpha spectral line of hydrogen.
Lunt-Solar-Systems – Exclusive European Distributor
Bresser GmbH
Gutenbergstrasse 2, D-46414 Rhede, Germany
Phone: +49 (0) 2872 – 80 740
E-Mail:info@bresser.de
www.bresser.de
References
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