Baader Planetarium's AstroSolar™ Safety Film delivers white light views of the Sun that are unmatched by any other objective solar filter or material. The views through AstroSolar display fine solar details, including fine penumbral detail, solar granulation, and lighter colored faculae. The disk is set against a dark background, free of the haze and scatter that is common in typical 'mylar' films or inexpensive glass filters. The performance of AstroSolar is even more remarkable when considering its very low cost - only $36 for telescopes up to 8".
When combined with Baader's tips for a simple do-it-yourself filter mount, anyone can construct a complete low cost - High Quality - white light solar filter for any telescope.
It is possible to further improve the stability and sharpness of the solar image through the use of the Baader Solar Continuum Filter. Views of granulation and faculae are particularly enhanced through the use of this filter, in combination with AstroSolar. Users of achromatic refractors will be particularly pleased with the performance using this additional filter.
This highest precision film consistently produces strehl ratios of 94 to 96 percent in interferometric tests - thus it performs optically as well as a high quality Fluorite Triplet Lens by Carl Zeiss (per interferometric test results). Baader even had a hard time themselves seeing any difference in performance between AstroSolar™ and 1/20 wave precision optical windows which they stocked from Zeiss. Their stock of precision polished plates runs into tens of thousands of $ - all stocked for the 1999 eclipse - but AstroSolar™ was so good in fact, that these plates were hard to sell. Baader AstroSolar Safety Film shows notably more sharpness and contrast than any competitive objective filter we know of, especially including the affordable Glass Objective Filters and other commonly available Mylar filters.
What is even more important - with AstroSolar™ the Sun appears in it' s real color - neutral white (with only a slight bluish tinge). Other films and glass filters produce a blurry bluish or reddish/orange/yellow Solar image, thereby cutting part of the spectrum. Especially with an orange sun, it is very hard to see faculae regions which are visible predominantly in the blue wing of the spectrum.
Due to it's neutral color balance, AstroSolar enables the use of various color (or interference) filters which allows the observer to concentrate on certain spectral passbands for investigations of different layers within the solar "atmosphere".
AstroSolar™ is essentially free from pinholes, since - unlike even the most expensive glass filters - it is coated on both sides, so that the chance of two pinholes overlapping each other is extremely faint. Pinholes do appear, but to 1 out of 10000 only, in optical density 2.5!
This foil is intended for solar viewing with optical instruments (telescopes, binoculars, cameras). AstroSolar® Safety Film 5.0 is not authorized to be used for naked eye solar observation or production of solar viewers. For direct solar viewing without telescope, binocular or camera optics, inquire for our EN ISO 12312-2:2015 certified Baader Solar Viewers equipped with AstroSolar® Silver/Gold Film.