All sales of solar gear are final, so please choose your filter carefully and reach out with any questions.

Description:

The ASTF family of solar filters is constructed in a more elaborate manner than either the ASSF or ASBF and should be considered if you will be observing in extreme temperatures.. AstroSolar® must not be put under stress, neither during mounting the film, nor during any temperature change. For this reason the ASTF Filter features a temperature-compensated cell. The film itself is repeatably cemented onto an injection molded ring, whereas the substrate of that ring has the same thermal expansion as the Astro Solar® Filter material itself. This free floating film-carrier ring is held onto the aluminum frame with the help of another holding ring made of fiber reinforced plastic - for a maximum of security against breaking of the cell. This temperature compensated cell enables the AstroSolar® filter material to retain its excellent optical quality at any temperature - be it -30 degrees C or 50 degrees C.

• Safe for solar observation and photography with all high-end telescopes and extreme tele-lenses
• OD 5.0, mounted stress free in a temperature compensated cell
• Suitable for highest magnifications and detailed observation of individual sunspots
• No astigmatism during winter observation or with temperature changes in summer
• What's included: ASTF Filter (with apertures from 80 to 280mm) comes with two sets of centering bolts in 38mm length; 3 bolts with 10mm diameter and 3 bolts with 20mm diameter, adjustable to the unused tube diameter of your telescope or dew cap. In addition, three safety straps with glue-pads and three rubber plugs to cover the unused holes.

• Use this to find the right filter size for your telescope!
• , PDF. Refer to this chart for the clamping range of all filters.

All Baader Solar Filters Feature:

• Original Baader (OD 5.0), cell-mounted and quality-inspected by skilled members of Baader Planetarium staff
• Clear white IR-rejecting front ring with reinforced raised edges along the outer and inner circumference, designed to protect the solar filter material from contact with any sharp metal edge
• Three (3) injection molded centering-bolts with threaded brass inserts to center the filter-cell in front of the tube opening. These bolts come in three different diameters, depending on the filter category (ASTF/ASSF/ASBF). Each bolt features injection molded rubber grip-faces, shaped to easily slide onto any telescope tube - but to remain firmly mounted
• No tool mounting and adjustment of the centering bolts to fit a wide variety of mechanical tube diameters. Bolts made to contact the outside or optional (if appropriate) the inside of the optical instrument tube. Refer to for further details.

• Non-rotating sliding fasteners made from aluminum that hold the centering bolts. These metal sliders are equipped with a machined indicator to point towards the adjustment index
• Additional Phillips screws are integrated into the sliding fasteners, so that the centering bolts can be firmly fastened with a screw driver if preferred by the user
• Index scale provided beside each adjustment slot - adjacent to each sliding fastener, for fast and repeatable adjustment of the filter cell onto different telescope tubes
• Black, sliding washers supplied to securely cover the full length of the adjustment slots in the aluminum frame - for blocking sunlight from passing through the filter cell beside the filter area

• Three (3) security straps included, to secure the position of the filter cell with Velcro-adhesive pads. A safety feature to absolutely ensure a secure fit in front of the telescope under any circumstances (ex. gust of wind)
• Only for ASTF-filters: rubber plugs supplied as cover for closing unused adjustment slots in the aluminum frame
• Warning text printed onto the front side of each filter cell: Read the Instructions before use
• Cardboard gift box fit for safely shipping and storing the filter