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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Baader AstroSolar Telescope Filter OD 5.0 - 80-280mm
Baader AstroSolar Telescope Filter OD 5.0 - 80-280mm
Baader AstroSolar Telescope Filter OD 5.0 - 80-280mm
Baader AstroSolar Telescope Filter OD 5.0 - 80-280mm
Baader AstroSolar Telescope Filter OD 5.0 - 80-280mm

Baader AstroSolar Telescope Filter OD 5.0 - 80-280mm

by Baader Planetarium
SKU BAA-2459310
$101.00 - $249.00
$101.00
$101.00 - $249.00
$101.00
Price Match Policy!
  • Enables safe, high-resolution solar viewing and imaging
  • Optical Density 5.0, blocking 99.999% of sunlight
  • Available in apertures from 80mm to 280mm
  • Temperature-compensated cell ensures optical quality from -30°C to +50°C
  • Stress-free film mounting preserves diffraction-limited resolution
3 in stock
Qualifies for FREE Shipping in CONUS on orders over $350.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Baader AstroSolar Telescope Filter OD 5.0 - 80-280mm

    The Baader AstroSolar Telescope Filter delivers diffraction-limited solar views by mounting genuine AstroSolar Safety Film (OD 5.0) in a cell engineered to eliminate mechanical stress. Available in sizes from 80mm to 280mm, this filter maintains its optical figure across a wide temperature range, from -30°C to +50°C. Each filter includes two sets of adjustable centering pins (10mm and 20mm diameter) and three safety straps, ensuring a secure fit to your telescope's tube or dew shield for uncompromising safety and image sharpness.

    Diffraction-Limited Views: The Stress-Free OD 5.0 AstroSolar Film Cell

    Unlike DIY or improperly mounted filters that stretch the film taut like a drumhead, Baader's ASTF filters mount the OD 5.0 AstroSolar film with zero tension. This proprietary, temperature-compensated cell allows the film to "float," preserving its sub-micron surface accuracy and acting as a high-precision optical window. The result is the ability to resolve fine solar details like granulation and sunspot penumbrae, which are often blurred into mush by the microscopic distortions induced by a stretched film.

    Universal Mounting with 10mm & 20mm Centering Pins

    Each ASTF filter ensures a secure, centered fit on a wide range of telescope tubes and dew shields. The package includes two sets of 38mm long centering pins—three with a 10mm diameter and three with a 20mm diameter—that slide into the filter's aluminum frame. This adjustable system, combined with the included safety straps, provides a reliable, non-slip attachment to your instrument, preventing accidental dislodging during observation.

    Baader ASTF vs. DIY Filters: Why Wrinkles Equal Sharpness

    A common misconception is that solar film should look perfectly flat like a glass filter. In reality, the slight waves and wrinkles visible in the AstroSolar film are proof that it is mounted correctly and free from tension. When film is stretched to look flat, it introduces astigmatism and other aberrations that degrade the image at the focal plane. The Baader ASTF filter cell is purpose-built to maintain this crucial, stress-free state, delivering image quality that stretched, DIY filters cannot match at high magnification.

  • Is the Baader AstroSolar OD 5.0 filter safe for looking at the Sun?

    Absolutely. The "OD 5.0" designation means the filter has an Optical Density of 5.0, which blocks 99.999% of all sunlight, including harmful UV and IR radiation. This makes it completely safe for direct visual observation and photography, provided it is mounted securely to the front of your telescope and is free of any pinholes or damage.

    Why does the film on my Baader AstroSolar filter look wrinkled?

    The wrinkles are a sign that the filter is working correctly. Baader's design intentionally mounts the AstroSolar film without any tension. This stress-free state is essential to preserve the film's diffraction-limited optical quality. Stretching the film to make it look flat would introduce distortions and ruin high-magnification views.

    How do I choose the right size Baader AstroSolar filter for my 8-inch SCT?

    You need to measure the outer diameter (OD) of your telescope's front cell or dew shield. For an 8" SCT, this is typically around 9.25" or 235mm. You would select the Baader ASTF 240mm filter, which is designed for tube ODs from 260-300mm. Always choose the filter size that allows the centering pins to grip the outside of your telescope tube securely. Refer to the specific fitment range for each filter size.

    Can I use the Baader AstroSolar OD 5.0 filter for photography?

    Yes, the OD 5.0 AstroSolar filter is excellent for both visual observation and high-resolution solar photography (white-light). It allows for short exposure times necessary to "freeze" atmospheric seeing, making it ideal for capturing sunspots, faculae, and solar granulation with a planetary camera or DSLR.

    What is the difference between this Baader filter and a cheaper glass solar filter?

    Baader's AstroSolar film provides superior optical quality to most affordable glass filters. The film is manufactured to diffraction-limited standards, while many glass filters use lower-grade "plate glass" that can soften fine details. The Baader ASTF filter consistently delivers sharper, higher-contrast images of the Sun's surface.

    Will this Baader filter show granulation on my 100mm refractor?

    Yes, under conditions of good atmospheric seeing, a 100mm refractor equipped with a Baader AstroSolar filter is more than capable of resolving the Sun's granulation pattern. The filter's high optical quality will not be the limiting factor; the sharpness will be determined by the stability of the air and the quality of your telescope's optics.

  • Optical Density OD 5.0 (99.999% light reduction)
    Available Apertures 80mm, 100mm, 120mm, 140mm, 160mm, 180mm, 200mm, 240mm, 280mm
    Film Material Baader AstroSolar Safety Film
    Mounting Temperature-compensated, stress-free cell
    Operating Temperature -30°C to +50°C
    Included Pins 3x 10mm diameter, 3x 20mm diameter (38mm length)
    Net weight (kg) 0.12 (80mm)
    0.16 (100mm)
    0.17 (120mm)
    0.20 (140mm)
    0.22 (160mm)
    0.23 (180mm, 200mm)
    0.28 (240mm)
    0.33 (280mm)
    Outer Diameter 170 (80mm)
    190 (100mm)
    210 (120mm)
    230 (140mm)
    250 (160mm)
    270 (180mm)
    290 (200mm)
    330 (240mm)
    370 (280mm)
    Usage Visual solar observation and imaging at high magnification
    Solar Wavelength Whitelight (integral light)
    Solar Filter with mount/thread? Yes
    Outer Clampingrange (10mm bolts) 110 – 140 (80mm)
    130 – 160 (100mm)
    150 – 180 (120mm)
    170 – 200 (140mm)
    190 – 220 (160mm)
    210 – 240 (180mm)
    230 – 260 (200mm)
    270 – 300 (240mm)
    310 – 340 (280mm)
    Inner Clampingrange (10mm bolts) 130 – 160 (80mm)
    150 – 180 (100mm)
    170 – 200 (120mm)
    190 – 220 (140mm)
    210 – 240 (160mm)
    230 – 260 (180mm)
    250 – 280 (200mm)
    290 – 320 (240mm)
    330 – 360 (280mm)
    Outer Clampingrange (20mm bolts) 100 – 130 (80mm)
    120 – 150 (100mm)
    140 – 170 (120mm)
    160 – 190 (140mm)
    180 – 210 (160mm)
    200 – 230 (180mm)
    220 – 250 (200mm)
    260 – 290 (240mm)
    300 – 330 (280mm)
    Inner Clampingrange (20mm bolts) 140 – 170 (80mm)
    160 – 190 (100mm)
    180 – 210 (120mm)
    200 – 230 (140mm)
    220 – 250 (160mm)
    240 – 270 (180mm)
    260 – 290 (200mm)
    300 – 330 (240mm)
    340 – 370 (280mm)

    • ASTF Solar Filter

      × 1

    • Centering Pins (10mm dia, 38mm length)

      × 3

    • Centering Pins (20mm dia, 38mm length)

      × 3

    • Safety Straps with Self-Adhesive Pads

      × 3

    • Rubber Plugs for Unused Holes

      × 3

    • Instruction Manual

      × 1

  • Baader Planetarium Warranty