All in one!
An H-alpha filter system consists of several elements:
• The etalon filter is the actual H-alpha filter. As an interference filter, it cancels out all
wavelengths except the H-alpha line. Its filter effect depends on the filter thickness
and is automatically controlled by the temperature control.
• The telecentric system provides the parallel beam of light path which is necessary
for the etalon to function properly. A Barlow lens or even a telescope with f/30 pro-
vides the necessary focal ratio, but not the necessary parallel beam of light.
• The blocking filter reflects the
incident sunlight just in front of
the etalon and the telecentric. This
protects the etalon from excessive
heat. In addition, an etalon also
transmits wavelengths that are
many times the desired transmissi-
on line; these are also blocked by
the blocking filter.
• The D-ERF energy rejection filter
is mounted in front of the telescope
and protects the filter system from
unnecessary solar energy by al-
lowing only red light to pass.
With the SunDancer II, the etalon,
telecentric system and blocking filter form one unit; on telescopes with a maximum
aperture of up to 80 mm, the energy protection filter can be omitted if necessary (see
chapter "Choosing a Dielectric Energie Rejection Filter"). The result: easier handling
and lower entry costs!
Schematic Structure of A H-alpha-Telescope with
SunDancer II Filter
A D-ERF filter is only necessary on telescopes with
more than 80 mm aperture. With an optional aperture
baffle or iris diaphragm, the telescope can be stopped
down to the ideal focal ratio of f/10.
Red: Components of the SunDancer II.
Yellow: Optional accessories.
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Manual: SunDancer II
SunDancer II at a telescope with mirror star diagonal.
Hand control and power supply are stored in the yellow bag.
Eyecup with
Folding Wing
Eyepiece
Focusing
Eyepiece Holder
(# 2458125)
Research Grade
H-alpha 0.4x
Telecompressor 2"
Ba e (Ø19mm)
Etalon (Ø25mm)
Micrometer Screw
tiltable, heated
Achromatic 3x
Telecentric System
2nm H-alpha
Blocking Filter
(Ø12mm)
Scope of Delivery
of the SunDancer II
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2
1. SunDancer II H-alpha-filter unit comprising the blocking filter, 3x telecentric system
and focusing eyepiece holder
# 2458125
2. Temperature control box (hand control)
3. Power supply (with international adapters)
4. Carrying case
5. Baader Utility Bag
# 2954201
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3
5
© Baader Planetarium GmbH | 2021
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