This solar filter can be combined with almost all standard refractors.
Unlike other H-alpha filters, this filter has no central obstruction, which is a clear advantage in terms of contrast and sharpness.
The manufacture of this type of solar filter is therefore more difficult and expensive than filters from other manufacturers, and greater attention must be paid to optical quality and mechanical accuracy during production.
The result is that larger filters from other manufacturers, which cost the same or even more, cannot match the sharpness and contrast of this filter.
By using a second Etalon filter, the spectral range is reduced to a half-width of 0.5Å. The prominences are then no longer quite as easy to see, but the surface details gain extremely in contrast. To observe the prominences, the second Etalon filter can simply be unscrewed.
The scope of delivery consists of a 70 mm Fabry-Perot Etalon filter doublestack with a surface accuracy of Lambda 1/100, a 20 mm blockfilter in a 2" holder for rear insertion into the telescope, and a 2"-1.25" reduction adapter.
Not included in the delivery is a corresponding adapter plate for attaching the filter in front of the objective. These are available as standard for most common telescope manufacturers.
Our expert comment:
Solarscope undoubtedly manufactures the best solar telescopes and solar filters currently available.
The sharpness and contrast of these Etalon filters are impressive, partly due to the obstruction-free optics, but in my opinion, this is largely due to the quality of these filters. At Solarscope Ltd., the flat discs for the Etalon are polished to 1/100 lambda – I don't know of any other manufacturer who would do this.
Even though Solarview filters and telescopes are more expensive than those of other manufacturers with the same aperture, I can recommend them without hesitation. You would have to buy a much larger and therefore more expensive filter to achieve the same image quality.
(Anderl Rodoschegg)
