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Baader Planetarium ASTF 80 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium Baader ASTF 100 AstroSolar® Telescope Filter (OD 5.1)
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 120 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 140 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 160 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 180 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 200 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 240 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 280 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 80 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium Baader ASTF 100 AstroSolar® Telescope Filter (OD 5.1)
Baader Planetarium ASTF 120 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 140 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 160 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 180 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 200 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 240 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite
Baader Planetarium ASTF 280 – AstroSolar® Telescope Filter OD 5.1 – ClearWhite

Baader Planetarium ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite

by Baader Planetarium
SKU BAA-2423010
CA$142.00 - CA$344.00
CA$142.00
CA$142.00 - CA$344.00
CA$142.00
Price Match Policy!
  • Available in nine sizes from 80mm to 280mm (ASTF 80 to ASTF 280) to suit your telescope
  • AstroSolar® Safety Film with Optical Density 5.1
  • Diffraction-limited optical quality for high-resolution views
  • Temperature-compensated filter cell keeps the film tension-free
  • Produces a neutral, ClearWhite image of the solar disk
  • Includes adjustable centering bolts and safety straps for secure attachment
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  • Description
  • FAQ
  • Specifications
  • In the Box
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  • Warranty

  • ASTF – AstroSolar® Telescope Filter OD 5.1 – ClearWhite

    The Baader ASTF AstroSolar® Telescope Filters deliver safe, diffraction-limited white-light solar viewing and are available in nine sizes, from the ASTF 80 for 80mm-class telescopes up to the ASTF 280 for 280mm (11-inch) instruments. Their renowned AstroSolar® film features an Optical Density of 5.1, safe for direct visual observation through the telescope and for solar photography, while rendering high-contrast, neutral white-light images of sunspots, granulation, faculae, and the partial phases of solar eclipses.

    AstroSolar OD 5.1 Film: Diffraction-Limited White-Light Views

    At the heart of every ASTF filter is Baader's AstroSolar® Safety Film, which achieves the optical quality of a high-precision, plane-parallel glass filter without the associated cost. It blocks harmful ultraviolet and infrared radiation, and unlike many lesser filters that produce an orange-tinted, low-contrast image, it delivers a "ClearWhite" view, showing the Sun in its natural color for objective analysis and photography.

    Temperature-Compensated Cell for Consistent Optical Integrity

    To maintain its diffraction-limited performance, AstroSolar® film must remain completely free of tension. Every ASTF filter features an advanced, temperature-compensating cell that allows the film to "float." The film is mounted on an injection-molded ring with the same thermal expansion properties, which is then held within the aluminum frame by a separate glass-fiber-reinforced ring. This design ensures the film never stretches or shrinks due to temperature changes, preserving its exquisite image quality from a frigid -30°C to a scorching +50°C.

    ASTF vs. DIY Filters: The Critical Role of a Tension-Free Mount

    Many homemade solar filters stretch the film taut like a drum skin in an attempt to make it look flat like glass. This process completely destroys the film's optical properties, resulting in blurry views unsuitable for high magnification. A correctly mounted AstroSolar® filter will exhibit slight waves; this is a sign that the film is tension-free and ready to perform as a precision optical window. The professional construction of the ASTF cell removes the guesswork and risk, guaranteeing optimal performance in every size.

    Secure and Adaptable Mounting System for Telescopes

    Each ASTF filter is equipped with a robust and versatile mounting system to ensure a safe, secure fit on your telescope's tube or dew shield. Adjustable centering bolts slide into the aluminum frame to center and clamp the filter on your instrument; the ASTF 120 and ASTF 200, for example, come with two sets of three 38mm-long bolts in 10mm and 20mm diameter, plus rubber plugs for unused openings. For added peace of mind, included safety straps with adhesive pads anchor the filter to your telescope, preventing it from being accidentally dislodged by wind or a sudden bump.

  • Why does the film in my ASTF filter look wrinkled?

    This is intentional and a sign of correct mounting. For the AstroSolar® film to deliver diffraction-limited images, it must be completely free from tension. The slight waves indicate the film is "floating" in its temperature-compensated cell, ready to perform like a high-precision optical window. A taut, perfectly flat film would produce a poor image.

    What is the difference between an ASTF filter and a simple glass solar filter?

    Baader ASTF filters use diffraction-limited AstroSolar® film, which acts as a precision optical window, providing much higher contrast and resolution than most affordable glass filters. The film also produces a neutral white image, whereas many glass filters add a strong orange or yellow color cast.

    How do I attach an ASTF filter securely to my telescope?

    Slide the adjustable centering bolts into the filter frame and position them so they grip the rim of your telescope tube or dew shield for a snug, centered fit. For maximum safety, you must also use the included safety straps, which create a secure connection between the filter cell and the telescope tube, preventing accidental removal by wind or a bump.

    Can I use the Baader ASTF filters for solar photography?

    Absolutely. The Optical Density 5.1 film is designed for both visual observing and high-resolution solar photography. Its high-contrast, neutral color image is ideal for capturing fine details like sunspot umbra and penumbra, faculae, surface granulation, and planetary transits with a DSLR or dedicated astronomy camera.

    Which ASTF size should I choose for my telescope?

    The ASTF range covers telescope classes from 80mm (ASTF 80) to 280mm (ASTF 280), e.g. small refractors, 8-inch Schmidt-Cassegrains and Dobsonians, and 11-inch SCTs. Because the filter clamps around the front of your instrument, always measure the outer diameter of your telescope tube front or dew shield before ordering to ensure a proper fit.

    Is an ASTF filter safe for viewing a total solar eclipse?

    ASTF filters are essential and perfectly safe for viewing all the partial phases of an eclipse. However, you MUST remove the filter from the telescope the moment totality begins to see the faint solar corona. As soon as the sun begins to reappear from behind the moon, the filter must be securely replaced immediately.

  • Usage Visual solar observation and imaging at high magnification
    Solar Wavelength Whitelight (integral light)
    AstroSolar Film AstroSolar Safety Film
    Optical Density 5.1
    Solar Filter with mount/thread? Yes
    Available Clear Apertures 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, 200mm, 240mm, 280mm
    80mm
    Net weight (kg) 0.12
    Filter size 80 mm
    Inner Diameter / Clear Aperture (mm) 80
    Outer Diameter 170 mm
    Outer Clampingrange (10mm bolts) 110 – 140 mm
    Inner Clampingrange (10mm bolts) 130 – 160 mm
    Outer Clampingrange (20mm bolts) 100 – 130 mm
    Inner Clampingrange (20mm bolts) 140 – 170 mm
    100mm
    Net weight (kg) 0.16
    Filter size 100 mm
    Inner Diameter / Clear Aperture (mm) 100
    Outer Diameter 190 mm
    Outer Clampingrange (10mm bolts) 130 – 160 mm
    Inner Clampingrange (10mm bolts) 150 – 180 mm
    Outer Clampingrange (20mm bolts) 120 – 150 mm
    Inner Clampingrange (20mm bolts) 160 – 190 mm
    120mm
    Net weight (kg) 0.17
    Filter size 120 mm
    Inner Diameter / Clear Aperture (mm) 120
    Outer Diameter 210 mm
    Outer Clampingrange (10mm bolts) 150 – 180 mm
    Inner Clampingrange (10mm bolts) 170 – 200 mm
    Outer Clampingrange (20mm bolts) 140 – 170 mm
    Inner Clampingrange (20mm bolts) 180 – 210 mm
    140mm
    Net weight (kg) 0.20
    Filter size 140 mm
    Inner Diameter / Clear Aperture (mm) 140
    Outer Diameter 230 mm
    Outer Clampingrange (10mm bolts) 170 – 200 mm
    Inner Clampingrange (10mm bolts) 190 – 220 mm
    Outer Clampingrange (20mm bolts) 160 – 190 mm
    Inner Clampingrange (20mm bolts) 200 – 230 mm
    160mm
    Net weight (kg) 0.22
    Filter size 160 mm
    Inner Diameter / Clear Aperture (mm) 160
    Outer Diameter 250 mm
    Outer Clampingrange (10mm bolts) 190 – 220 mm
    Inner Clampingrange (10mm bolts) 210 – 240 mm
    Outer Clampingrange (20mm bolts) 180 – 210 mm
    Inner Clampingrange (20mm bolts) 220 – 250 mm
    180mm
    Net weight (kg) 0.23
    Filter size 180 mm
    Inner Diameter / Clear Aperture (mm) 180
    Outer Diameter 270 mm
    Outer Clampingrange (10mm bolts) 210 – 240 mm
    Inner Clampingrange (10mm bolts) 230 – 260 mm
    Outer Clampingrange (20mm bolts) 200 – 230 mm
    Inner Clampingrange (20mm bolts) 240 – 270 mm
    200mm
    Net weight (kg) 0.23
    Filter size 200 mm
    Inner Diameter / Clear Aperture (mm) 200
    Outer Diameter 290 mm
    Outer Clampingrange (10mm bolts) 230 – 260 mm
    Inner Clampingrange (10mm bolts) 250 – 280 mm
    Outer Clampingrange (20mm bolts) 220 – 250 mm
    Inner Clampingrange (20mm bolts) 260 – 290 mm
    240mm
    Net weight (kg) 0.28
    Filter size 240 mm
    Inner Diameter / Clear Aperture (mm) 240
    Outer Diameter 330 mm
    Outer Clampingrange (10mm bolts) 270 – 300 mm
    Inner Clampingrange (10mm bolts) 290 – 320 mm
    Outer Clampingrange (20mm bolts) 260 – 290 mm
    Inner Clampingrange (20mm bolts) 300 – 330 mm
    280mm
    Net weight (kg) 0.33
    Filter size 280 mm
    Inner Diameter / Clear Aperture (mm) 280
    Outer Diameter 370 mm
    Outer Clampingrange (10mm bolts) 310 – 340 mm
    Inner Clampingrange (10mm bolts) 330 – 360 mm
    Outer Clampingrange (20mm bolts) 300 – 330 mm
    Inner Clampingrange (20mm bolts) 340 – 370 mm

    • ASTF 80 – AstroSolar® Telescope Filter (80mm)

      × 1

    • ASTF 120 AstroSolar® Telescope Filter (120mm)

      × 1

    • Centering Bolts (10mm Diameter) (120mm)

      × 3

    • Centering Bolts (20mm Diameter) (120mm)

      × 3

    • Safety Straps with Adhesive Pads (120mm)

      × 3

    • Rubber Plugs for Unused Holes (120mm)

      × 3

    • Mounting Instructions (120mm)

      × 1

    • ASTF 240 AstroSolar® Telescope Filter (240mm)

      × 1

    • Centering Pins (sets) (240mm)

      × 2

    • Safety Straps with Adhesive Pads (240mm)

      × 3

    • Rubber Plugs for Unused Holes (240mm)

      × 3

    • Mounting Instructions (240mm)

      × 1

  • Baader Planetarium Warranty