Available again soon - Baader Planetarium AstroSolar safety film for solar observation with telescopes in a 20cm x 30cm sheet. It is made for the construction of high-quality objective-filters for observing the sun with telescopes, binoculars, camera or video-lenses. This foil is CE-tested and reduces the intensity of sunlight by 99.999% (neutral density 5.0).
Baader Planetariums AstroSolarTM safety film is a specially manufactured streak- and blister free foil. It attains the optical performance of planeparallel glass filters. The base material is not "Mylar"!. The basic development of this film was made in laboratories for nuclear- and particle physics.
A New Standard in Solar Filters (review in Sky&Telescope 9/2000)
High density coatings on both sides of the foil ensures a highly uniform filtering, while neutralizing the occasional miscroscopic holes in the coating. The image of the sun is extremely contrasty and of almost neutral colour.
Optical quality:
This highest precision film consistently produces strehl ratios of 94 to 96 percent at interferometric tests - thus it performs optically like a Fluorite Triplet Lens by Carl Zeiss or Astro Physics (Interferometric test results). Unfortunately we have a hard time ourselves to see any difference in performance between AstroSolar and 1/20 wave precision optical windows which we are stocking here from Zeiss. Our stock of precision polished plates runs into tens of thousands of pounds - all stocked in for the 1999 eclipse - but AstroSolar was so good in fact, that these plates are hard to sell. Our Safety Film shows notably more sharpness and contrast than any competitive product we know of, especially including all affordable US-Glass Objective Filters.
What is even more important - with AstroSolar the Sun appears in it' s real colour - neutral white. Other films and most glass filters produce a blurry bluish or reddish 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 colour balance, AstroSolar enables the use of various colour (or interference) filters which allows the observer to concentrate on certain spectral passbands for investigations of different layers within the solar "atmosphere".
Eye safety:
AstroSolar is essentially free from pinholes, since - other than with 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! Baader AstroSolar safety film has been approved for eye safety by the National Bureau of Standards in Germany, the PTB. Unlike any other Solar Filter on the market, AstroSolar is CE-tested according to EG-Norm 89/686 and EN 169/92 ( notified body 0196). All processes connected to this product have been thoroughly tested. Coatings are inspected constantly for consistency to ensure your eye safety!
Supplied with instructions in single A4 size sheet and can be trimmed with scissors to fit
