Lunt Solar Systems * 2520 N. Coyote Dr. #111 Tucson, AZ 85745 * (520) 344-7348
2
SETTING UP FOR THE FIRST TIME
1.
Attach the telescope and clamshell to your mount of choice. There is a ¼-20 threaded hole on the underside of
the clamshell. Attach the scope directly to a photographic tripod or attach a Vixen-style or Losmandy-style dovetail
plate (whichever your mount requires) to the clamshell.
2.
Slide the Blocking Filter into the focuser and lock it down with the thumb screw. Insert a low power eyepiece (sold
separately) into the blocking filter. A 25 mm is a good choice for a large field of view.
3.
Attach a Tele Vue Optics Sol-Searcher finder to your telescope. The Sol-Searcher label will be facing outward,
towards the Sun. See the instruction sheet provided with the Sol-Searcher for complete instructions. If you do not
have a Sol-Searcher, you can use the shadow of the front lens cell cast by the Sun onto the clamshell of your
telescope. Center the shadow and you should be pretty close. Never attempt to use a conventional finder scope
to locate the Sun! Look through the eyepiece to improve your alignment of the telescope.
4.
Now
it’s time to focus. Your goal is to get the edge of the Sun as sharp as possible. Focus is achieved using the
helical style eyepiece focuser.
5.
Look through the eyepiece. Do you see a fuzzy red ball? If not, make sure you have removed the dust cap from
the front and check your alignment to the Sun. If the Sun is still not in the field of view of your eyepiece, move the
telescope around a little while you are looking through it. Be patient, you will find it! Once you do, center the Sun
and, if you have one, adjust the Sol-Searcher so that it is correctly aligned to your scope.
6.
Tune That Sun! Here is where the magic begins. On the side of the scope is a large black cylinder on a brass
barrel. This cylinder is the Pressure Tuning system for the LS50THaPT. The black handle of the cylinder has a
short start-thread attaching it to the brass cylinder. Unscrew the black handle completely. There may be some
resistance and a faint
“popping” sound. That’s normal when adjusting pressure for your altitude. Carefully install
the handle onto the cylinder, engaging the threads about one turn. While looking through the eyepiece, gently turn
the black handle clockwise onto the cylinder. There will be little resistance at first, but as the pressure in the
cylinder builds, the resistance increases slightly. As you turn the cylinder, centering the 656.28 nm wavelength on-
band, you should see features come into view. Continued tuning will result in the wavelength shifting past 656.28
nm, and details will begin to disappear. Fine-tune for the best images.
7.
When you feel you have tuned effectively, refocus the telescope. Try to relax your eye while observing and let the
details come to you. Once you are comfortable observing with a lower power eyepiece, try a 12 mm or other
higher power ocular. On days of good seeing, you can push the magnification higher than on days of poor seeing.
Remember, if you cannot achieve sharp focus, use a lower power eyepiece.
8.
A few details regarding Pressure Tuning:
The amount of pressure being supplied to the etalon cavity is minimal.
It’s the equivalent of going from 500 ft below sea level to about 10,000 ft above; just a few PSI. There is NO risk of
explosion, as this is 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. If the handle separates, simply thread it back on
1 turn.
It’s not necessary to re-set the system every time it is used. Re-setting may only be required if the
telescope has been idle for a long period of time. True Doppler Tuning (Pressure Tuning) provides more precision
for observing desired solar features than Tilt Tuning. It adds a 3D-like component to the viewing experience. While
it has minimal effect on prominences at the edge of the disk, it does have an effect on filaments and active
regions on the surface. While viewing a filament at the center of the Sun, the user has the ability to Doppler shift
from the base of the filament to the tip, following the
filament’s structure toward or away from you, providing
enhanced visual and imaging capability for the observer as well as a research tool for the avid hobbyist.
For More Information:
. Y
ou’ll find a very active forum and
interesting articles. Visit the Lunt Solar Systems blog at
http://luntsolarsystems.com/blog/
. Search the archives for your
favorite topics.