Baader AstroSolar Safety Film Filters are diffraction limited solar neutral density filters mounted in a temperature-compensated cell. This makes them extremely safe and protected against the normal stresses typical solar films are put under, as well as retaining the excellent optical quality at any temperature, be it -30 to +50C. No astigmatism is introduced during cold winters or hot summers.
Note: Price is for one piece only. For use with binoculars, two filters are necessary.
The AstroSolar filters are suitable for safe solar observation and photography with binoculars with apertures between 50 - 100mm as well as camera lenses. Velcro safety straps and pads and large centering bolts with rubber grips are included to secure the filters to your binoculars. The bolt slots have printed index scales to allow fast and repeatable adjustment. The white outer ring rejects infrared light and features raised edges along both the inner and outer circumference to protect the film.
The film itself is repeatably cemented onto an injection moulded ring, whereas the substrate of that ring has the same thermal expansion like the Astro Solar Filter material itself. This free floating film-carrier ring is held onto the aluminium frame with the help of an additional holding ring made of fiber reinforced plastic – for maximum security against breaking of the cell. This aluminium frame has a cutout on one side to facilitate use with binoculars.
Included are two sets of 38mm long centering bolts, three with 10mm diameter and three with 20mm diameter, along with three safety straps with glue-on pads.
WARNING: Make sure to read the included manual for important safety information before use. Testar does not take responsibility for damage caused by improper use. For more information, check out the AstroSolar website.
Click to open Baader's Solar Filter Finder Tool to find the correctly-sized filter for your instrument.
Table showing clamping ranges for each size of AstroSolar filter. Click to enlarge.
How to interpret the filter size table: Astrosolar filters include a set of rubber cylinders and have fine positioning slots, allowing you to clamp the filters over a large range. The cylinders can be positioned to clamp on the outside of your binocular (distance range in RED above) or on the inside of the tube with opposing force (in GREEN).
The number in the name of the filter (ie. ASBF 50mm) indicates the actual aperture of the filter material, not the diameter of the binocular lens. For example, if you have 10 x 42 binoculars, you need to measure the outer diameter of the binocular tube at the very front, which will be larger than 42mm. Then you can select the appropriate filter that will fit either on the outside of inside of the tube.
Though intended for binoculars, this was just right for the 60mm aperture of my Takahashi FOA-60Q. Now I'm ready to for quick solar viewing (sunspots) within minutes of deciding to, and at a reasonable price. Just needed to find a suitable container to store it, easily solved.