Baader SunDancer II 0.6 Angstrom H-Alpha Filter with Etalon from SolarSpectrum

Baader Sundancer II H-Alpha Solar Filter

The Baader SunDancer II (with heated H-alpha etalon from SolarSpectrum) transforms an existing telescope quickly and easily into a professional H-alpha telescope! For telescopes up to 80 mm aperture you don´t need any further accessories: The SunDancer II already includes an achromatic (!) 3x telecentric with T2 connector; the entire SunDancer is simply plugged between star diagonal and eyepiece and connected to a power source. It then automatically heats up to the optimal operating temperature. No readjustment is necessary even during long observations. Finetuning the transmission line to adapt to different telescope systems is possible via the control box; the micrometer screw can be used to quickly shift the transmission line into the blue wing of the H-alpha line to compensate for the Doppler effect during fast H-alpha events on the sun.

An additional D-ERF energy protection filter in front of the telescope is necessary only on telescopes with more than 80 mm aperture; alternatively, the telescope can be stopped down to 80 mm with an optional diaphragm front of the objective.

Power is supplied either via the included power supply unit or via an optional power tank. A detailed description of the possible applications and the requirements for the telescope can be found in the operating instruction under the "Downloads" tab.

The ideal focal ratio of the telescope for the filter:

The H-alpha filter has a half-width of 0.6 +/- 0.1 Å on telescopes with f/10. The telecentric extends the focal length of the telescope by a factor of three, so that the ideal focal ratio of f/30 for H-alpha is achieved on telescopes with f/10. The SunDancer II is recommended for telescopes up to about f/8 and is well usable up to about f/6.5. On faster telescopes, the half-width increases. The half-width was chosen in such a way so that both prominences and the solar surface are nicely displayed at the same time.

Photography with the SunDancer II

The H-Alpha filter has a male T2 thread on the camera side for camera connection. To achieve a larger field, the SolarSpectrum 0.4x telecompressor can be connected, # BA 2459260. The compressor is linked in the accessories section.

Resistant to aging, but protect from frost:

The dielectric coating of the blocking filter (instead of the usual silver coating) and airtight storage of the SolarSpectrum Etalon filter in oil prevent the ageing processes of simpler filter designs. With proper treatment, the SunDancer II will retain its performance for many years. Please note that the filter - just like any H-alpha filter with Fabry-Pérot etalon - must be protected from frost. It must not be stored below 0 °C, otherwise the oil composition will become sulky and push the optical elements apart, damaging the filter. Thermal insulation is necessary for use at lower temperatures.

Instruction

Baader Planetarium provides a manual which you can download as PDF here.