Please note: This product is currently not available in the US.
The filters of the ASTF series (AstroSolar Telescope Filters) are ideal for medium to large high-end telescopes: a very good telescope deserves a very good filter!
Safe solar observation and photography thanks to AstroSolar Safety solar filter film (OD 5.0). The film is mounted without tension, so that the coating cannot be damaged. The high-quality frame has strongly rounded edges that prevent damage to the film. In addition, the underside of the film is made of a plastic that has the same thermal expansion coefficient as the film. This ensures that heating by sunlight does not cause tension between the film and the filter.
Centring pins with screws and washers are included in the scope of delivery. The centring pins have a rubberised profile and can be adjusted to a wide range of tube diameters. This keeps everything rock-solid! For those who are still unsure, three safety straps are also included in the scope of delivery, which can be pulled over the pin heads and attached to the tube with Velcro fasteners.
Which filter is right for you? The number in the product title or under the "Technical Data" tab indicates the average telescope aperture for which the filter is suitable.
The opening range for which the filter is suitable is always ten millimetres above and below the specified centre opening. The exact dimensions can be found in the PDF file under the "Downloads" tab.
For the clamping range, i.e. the permissible diameter of your tube, a distinction is made between whether you want to clamp with the pins from the outside or from the inside. Both are possible. The filters in the ASTF series come with two sets of clamping pins with different diameters, allowing for even more mounting options.
To find the right filter, you can also use the Filter Finder Tool. Simply click on the graphic on the AstroSolar overview page.
