There are some H-alpha systems that also deliver impressive results at a much lower price. However, to make this possible, compromises are necessary in terms of image detail, resolution (maximum magnification), field size or durability, which we did not want to make with the SunDancer. As we all know, the last 10% of quality requires the highest effort... With the SunDancer, we want to maintain the same high quality standard for which the SolarSpectrum filters are known, so that our customers and dealers are do not have to cope with ageing ("rusting") filters or exchange orgies.
We are happy to explain the advantages of the SunDancer over competing models.
- The Sundancer front blocker-filter has a hard, non-ageing coating. The Quark H-alpha filter, for example, uses an entrance blocker filter with only 8.5 mm free aperture. As of this date, it consists of so-called "soft coatings". Such a soft filter can age so much that the system needs a new blocking filter after only a few years. For some other filters, too, reports of ageing or "rusting" filters can be found in the relevant forums - partly depending on the year of production. The blocker filter (i.e. heat protection filter) used in the SunDancer II has 12 mm free aperture (40 % more aperture) compared to the front-blocker filter used in the Quark and has 5 times the production costs - but above all it is hard-coated and can withstand the heat at this point in the light path of telescopes (having up to 80mm aperture) without ageing or fading, even without an additional D-ERF-filter. Even though the SunDancer itself is a new product, our many years of experience with the (considerably more expensive) filters from SolarSpectrum went into its design. The longevity of H-alpha systems is always a topic in the relevant forums, discussions can be found here, for example:
- The 3x telecentric system of the SunDancer II likewise has larger lens diameters and an optically more sophisticated construction. If necessary, it can be unscrewed from the actual etalon and replaced by a 4x telecentric system. (As of 2022, this TZ-4 is still in preparation. The blocker filter built into the 3x telecentric must be placed into the 4x telecentric in the process). With the larger telecentric system and the larger blocker filter, larger telescope apertures can be used (of course only with additional D-ERF front filters or with SC-Triband-optics) to achieve much higher resolution. The Quark in comparizon is not nearly as flexible as it does not allow to exchange the TZ-3 into a TZ-4 configuration because that telecentric system is fixed onto the etalon.
- Most H-alpha filters are only designed for telescope apertures up to 90 mm and therefore at best achieve ~ two arc seconds of resolution. The SunDancer can deliver 0.7 arc seconds of resolution on a 200 mm Triband SC-telescope – even more with a future TZ-4. See our customer reviews for triband optics
- The etalon itself is also of larger size and of a higher quality, provides more contrast and is finer and quicker to adjust due to the additional tilting device - you can shift the transmission window a little (for observing blue-shifted structures moving towards us) without having to wait each time for the new temperature to adjust.
Please note that these filters are natural products, as each etalon is made from a grown crystal. We test all filters to ensure that they are within the specified range of 0.6 +/-0.1Å. For best results, you may want to adjust the operating temperature (more on this in the instructions) so that the filter is optimally adapted to your particular system.
