Series filters ASTF (Astro Solar Telescope filters) are ideally suited for medium to large telescopes from the high-end range: A very good telescope earned a very good filter!
Secure solar observation and photography thanks AstroSolar Safety solar filter film (OD 5.0). The film is fitted free of tension, so that there can be no damage to the coating. The quality version has very rounded edges to prevent damage to the film. There is also the underside of the film of a plastic, which has the same coefficient of thermal expansion as the foil. This ensures that the heating does not pass through sunshine to tensions between the foil and the filter.
Supplied Pins are included with screws and washers. The centering pins have a rubberized profile and can be adjusted over a wide range on the tube diameter. This keeps bombproof! For the doubters even three safety belts are included, which can be pulled over the pin heads and secured with Velcro on the tube.
Which filter is right for you? The number in the product title, or under the "Technical data" indicates the average telescope aperture for which the filter is suitable.
The opening area for which the filter is suitable, is always ten millimeters above and below the specified central opening. The exact dimensions can be found in the PDF that can be found under the tab "Downloads".
For the clamping area, so the allowable diameter of your tube, a distinction is made, if you want to jam with the pins from the outside or from the inside. Both are possible. In the filters of ASTF series two sets of clamping pins with different diameters are included, so that there are even more variations for attachment.
To find the right filter, you can also use the Filter Finder tool. Just click simply on the picture on the [http://www.astroshop.de/teleskop-zubehoer/filter/sonnenfilter/folienfilter-in-fassungen/15_15_40_20/m,Baader-Planetarium "Astro Solar overview"].