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Baader ASBF 50 AstroSolar Binoculars Solar Filter - 50 mm - ASBF-50

SKU: BAD-ASBF-50
To ensure that the solar filter you buy will fit properly, please take a few moments and measure the outside diameter of your telescope, spotting scope or binoculars before you order. Remember, the solar filter needs to fit snugly around the front of the tube assembly that holds the optics. If the filter is slightly larger than its diameter, the filter can be made to fit by the addition of self-stick felt spacers to the inside of the cell. However, if the filter is too small it will not fit, and that would be a shame. So please, measure before you order. Thanks.

Baader AstroSolar White Light Solar Filters

The world's finest solar filter material, Baader AstroSolar Safety Film, is now available in a complete range of high-quality mounted Baader Solar Filters. Their innovative design and construction enables each filter to fit a wide range of instruments…from telescopes, to spotting scopes and camera Lenses, to binoculars. Each filter is precisely mounted at the factory onto special cells, guaranteeing a stress-free mounting that, unlike other mounted solar film filters, preserves the full optical quality of the Baader AstroSolar film.

Many ready-made filters stretch the filter material like a drumhead in order to make it look like a piece of glass. While it might look more pleasing to the untrained eye, the stretching process absolutely destroys the image quality, rendering the film useless for high magnification work. Baader AstroSolar is mounted entirely stress free in order to perform like a high precision plane-optical window; in other words, AstroSolar film must show slight ripples! When the film is put under stress by an improper cell mount its optical quality is degraded and it then performs just like a common glass filter made of untreated float glass.

With Baader Planetarium AstroSolar™, the color of the Sun is displayed as neutral white, which is its true color. Other films and most glass filters produce a blurry bluish, yellow-orange, or reddish Solar image, thereby cutting part of the spectrum. Especially with an orange sun, it is very hard to see faculae regions which are visible predominantly in the blue part of the spectrum.

Baader ASBF 50 mm Binocular AstroSolar Filter
Fits 55-70 mm OD & 81-96 mm ID
Binoculars & Camera Lenses

Baader ASBF AstroSolar Solar Filters are designed to fit binoculars or camera lenses. They are very similar to the Spotting Scope (ASSF) filters except that one side of the filter cell is flat so that it can be used with most any pair of binoculars, even when a short interpupillary distance is chosen (see images for an example).

If you are going to use this filter for binoculars, you will need to buy two...one for each side.

The Baader AstroSolar Safety Film (ND 5.0) is mounted at the factory onto a clear white, IR-rejecting plastic ring that has a similar thermal expansion coefficient to minimize thermal stress on the film. This ring is then attached to the aluminum front frame of the filter, providing a very rigid and stable filter cell.

Each Baader ASBF AstroSolar Filter comes with two different lengths of centering bolts (13 mm & 24 mm) to give you leeway for mounting on your binoculars or camera lens. These centering bolts, with their non-slip rubber facing, are used to make contact along the outside, or if feasible, the inside diameter of your instrument. Non-rotating sliding aluminum fasteners hold the centering bolts. Additional Phillips head screws are integrated into the sliding fasteners so that, if you wish, you can use a screwdriver to fasten the centering bolts firmly into place. An indexing system is in place to allow repeatable and fast adjustments of the filter cell if you use it on more than one instrument.

You will also receive three security straps which allows you to secure the position of the filter with Velcro-adhesive pads. This extra security feature ensures that the filter will stay put even in windy conditions.

Baader ASBF 50 mm Solar Filter Specifications

  • Best for Apertures: 40 mm - 60 mm
  • Filter Aperture: 50 mm or 1.97”
  • Outer Cell Diameter: 110 mm
  • Net Weight: 68 grams or 2.4 ounces
  • ID Clamping Range with 13 mm Bolt: 81 mm - 96 mm mm
  • OD Clamping Range with 13 mm Bolt: 55 mm - 70 mm

Check out the Baader Solar Filter Clamping Ranges for more information on filter installation, etc.