ASTF - Baader Solar Filter for Telescopes
ASTF - Baader Solar Filter for Telescopes
ASTF - Baader Solar Filter for Telescopes

Baader Planetarium

ASTF - Baader Solar Filter for Telescopes

Regular price
$ 84.00
Sale price
$ 84.00
Unit price

In Stock

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


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
    • AstroSolar® Safety Film 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.

All Baader Solar Filters Feature:

    • Original Baader AstroSolar® Safety Film (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 Clamping Range of Baader Solar Filters (inner/outer) 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

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