Alpine Astronomical 120mm Baader AstroSolar BDSF 3.8 White-Light Digital Solar Filter for Telescopes

BH #ALBDSF120 • MFR #BDSF-120
Alpine Astronomical
Alpine Astronomical 120mm Baader AstroSolar BDSF 3.8 White-Light Digital Solar Filter for Telescopes
Key Features
  • For Digital Imaging with Nighttime OTAs
  • For Detailed, High-Magnification Viewing
  • Broad-Band Neutral-White Color
  • Optical Density of 3.8
Unlike many white-light solar filters that produce views of the sun with a red-orange, bluish, or yellow tint, the Alpine Astronomical 120mm Baader AstroSolar BDSF 3.8 White-Light Digital Solar Filter reveals the sun in its natural white color. With an optical density of 3.8, this iteration is specifically designed for digital imaging of the sun and all phases of a solar eclipse through an optic like a telescope or extreme telephoto lenses — showing more surface details with greater clarity versus other types of solar filters. The filter is mounted onto a clear-white IR-rejecting plastic ring, which acts as stabilizing element for the filter cell, and the ring is in turn mounted onto the aluminum front frame. The thermal expansion coefficient of the plastic and the film are similar to minimize thermal stress on the film for increased resistance to developing pinholes or tears.
In Stock
$114.00
SAFETY FIRST: Observing the Sun without the proper protection may result in serious personal injury, including permanent eye damage and blindness, and/or damage to equipment. Never point an optic at the sun without an approved solar filter on the front of the optic. For direct solar viewing, viewing the sun through an optic, or when using cameras with an optical viewfinder, ensure your filter is ISO 12312-2 (also written as ISO 12312-2:2015) certified. Never use photographic neutral density filters for direct solar viewing, viewing the sun through an optic, or when using cameras with an optical viewfinder.

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Alpine Astronomical BDSF-120 Overview

Unlike many white-light solar filters that produce views of the sun with a red-orange, bluish, or yellow tint, the Alpine Astronomical 120mm Baader AstroSolar BDSF 3.8 White-Light Digital Solar Filter reveals the sun in its natural white color. With an optical density of 3.8, this iteration is specifically designed for digital imaging of the sun and all phases of a solar eclipse through an optic like a telescope or extreme telephoto lenses — showing more surface details with greater clarity versus other types of solar filters. The filter is mounted onto a clear-white IR-rejecting plastic ring, which acts as stabilizing element for the filter cell, and the ring is in turn mounted onto the aluminum front frame. The thermal expansion coefficient of the plastic and the film are similar to minimize thermal stress on the film for increased resistance to developing pinholes or tears.

With the ability to be installed on the outside or inside of an optical tube assembly, dew shield, or corrector plate retaining ring, this filter provides a safe way to view the sun through conventional nighttime telescopes. Recommended for apertures from 110-130mm, the filter is engineered with three centering bolts that can fit OTAs, dew shields or corrector plates with an outside diameter of 140-180mm, or an inside diameter of 170-210mm. Due to the shallow depth of the corrector plate on most catadioptric OTAs, for secure and safe use Alpine Astronomical only recommends outside mounting on Cassegrain-style telescopes.

This filter is only intended for digital imaging of the sun, and is not safe for direct solar viewing or for use on cameras with an optical viewfinder. Only use on cameras with an electronic viewfinder (EVF) or Live-View option. If you do not know what kind of viewfinder your camera has, do not use this filter.

Fit

  • For the correct fit, measure the outside or inside diameter of the dew shield/lens housing - including hardware like retaining rings and screw heads — and choose the size that matches the measurement with some extra room
  • When used on Schmidt-Cassegrain, Maksutov-Cassegrain, or other catadioptric OTAs, outside mounting is required as the limited depth of the front inside diameter prevents full and secure engagement of the centering bolts
  • Recommended for 110-130mm apertures
  • 170-210mm inside diameters
  • 140-180mm outside diameter

Alpine Astronomical BDSF-120 Specs

BandpassWhite-light, broadband
Clear Aperture120mm
Diameter210mm
Weight5.5 oz / 155.0 g
Packaging Info
Package Weight0.85 lb
Box Dimensions (LxWxH)10.1 x 9.8 x 1.3"
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YOUR RECENTLY VIEWED ITEMS

This lens filter description says it is intended ...

This lens filter description says it is intended solely for digital imaging and NOT viewing. DO you carry one that is safe for viewing?
Asked by: Ann
I am not sure what the outside diameter of your scope is but one of these should work: https://bhpho.to/2Itn87i
Answered by: John
Date published: 2019-10-07

My scope has a dew shield and the outer dim is ...

My scope has a dew shield and the outer dim is 145.5mm; so will this or another can fit safely and securely? Thanks
Asked by: Eyad
If your outer diameter is 145.5mm you need: Alpine Astronomical 140mm Baader AstroSolar BDSF 3.8 White-Light Digital Solar Filter for Telescopes BH #ALBDSF140 • MFR #BDSF-140 https://www.bhphotovideo.com/c/product/1348179-REG/alpine_astronomical_bdsf_140_baader_3_8_od_digital.html
Answered by: John
Date published: 2021-02-14

Will this fit my ES CF 102 Triplet?

Will this fit my ES CF 102 Triplet?
Asked by: Eyad
If a solar filter is not made specifically for a particular scope, then with any Solar filter, one needs to know the Exact Outside diameter of the telescope, & then know the exact outside diameter of the solar filter, so its fits Firmly & safely. Both manufacturers should be consulted.
Answered by: david
Date published: 2021-02-11
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