Baader Double Stacked Solar Continuum Filter - 1.25" # FSOL-1D 2458392

Please note: For safe use while viewing or imaging the Sun, the Solar Continuum filter must be used in conjunction with a primary solar filter such as a Herschel Wedge Prism, or Baader AstroSolar Film (provided). The Solar Continuum filter must be placed after the primary filter (i.e. on the eyepiece), and cannot be used alone, or permanent eye and equipment damage will result.

The double stacked version of the Baader Planetarium Solar Continuum filter is designed to enhance the visibility of solar granulation and sunspot details. It consists of two 1.25" standard Baader Solar Continuum filters that are slightly tilted against each other and held in a special cell. This double stacking significantly boosts contrast and reduces the effects of atmospheric turbulence (seeing). The filter transmits only a specific spectral wavelength centered at approximately 535nm without emission and absorption lines. With the filter attached to a 1.25” eyepiece or camera nosepiece, images snap into focus. Flares on the solar limb, granulation, and fine detail at the rim of sun spots become more clearly visible. Details at the limit of focus become easier to hold and image motion caused by atmospheric turbulence is reduced.

The Solar Continuum filter works well for both visual and imaging with all types of telescopes. Users of SCTs and achromatic refractors will find it particularly beneficial, as it completely excludes the red and blue wavelengths, and centers on the peak visual wavelengths where the telescope optics are sharpest and free from chromatic aberrations. For imaging, we also recommend the Continuum filter be combined with a UV/IR Cut filter to eliminate the far infrared wavelengths that can cause parts of the image to appear out of focus. A 200mm x 290mm (8x11inch) sheet of Baader's renowned AstroSolar Photo Film (ND=3.8) is provided with each Solar Continuum filter. This material may be easily mounted to any telescope using provided instructions.

The Solar Continuum filter can also be used to test the quality of telescope optics using a bright star. Its narrow bandpass and complete blockage of longer and shorter wavelengths make it superior to standard green colored filters for testing refractors at their center design wavelength - the peak visual wavelength. Accurate evaluation of optical quality for a telescope can be made without the effects of spherochromatism (chromatic spherical aberration) also known as secondary color error. Star testing through the Solar Continuum filter will require a bright test star due to the limited amount of light allowed through the double stacked configuration and also due to the narrow 10nm bandpass.

As with all Baader Planetarium filters, the Solar Continuum possesses all of the trademark Baader filter qualities. Optical, physical, and mechanical qualities are superb.

Manufacturer part numbers: FSOL-1D or 2458392.

Agena Note: Please note that this filter does not feature a female thread. Hence, you cannot stack additional 1.25" filters on to this item.