Baader Planetarium Filters

Durable dielectric coatings for a lifetime of service. Plane-parallel polished substrates for the highest level of optical performance. Precise glass thickness of 2 mm for 1.25" and 2" mounted filters, and 3 mm for 50.8 mm round unmounted filters to make the filters par-focal within each respective size for imaging applications.

Nebula Filters
  • Visual Narrowband O-III Filter 1.25" (BPO3125) and 2" (BPO32)
  • UHC-S High Transmission Nebula Filter 1.25" (BPUHCS125) and 2" (BPUHCS2)

  • Colored and Contrast Filters
  • Colored Filters 1.25" (BPCF125) and 2" (BPCF2)
  • Contrast-Booster Filter 1.25" (BPCB125) and 2" (BPCB2)
  • Neodymium ("Moonglow & Skyglow") Filter 1.25" (BPMS125) and 2" (BPMS2)
  • Semi-APO Filter - 2" (BPSAPO2)

  • Filters for Lunar / Solar Studies
  • 2" Neutral Density 1.8 Filter (BPND18)
  • Polarizing Filter 1.25" (BPPOL125) and 2" (BPPOL2)
  • Solar Continuum Filter 1.25" (BPSC125) and 2" (BPSC2)

  • CCD/Webcam Imaging Filters
  • H-Alpha Pass Filter - 35 nm 2" (BPHA2)
  • Narrowband Oxygen III Filter for CCD Imaging - 2" (BP03285)
  • IR Pass Filter 1.25" (BPIRP125) and 2" (BPIRP2)
  • U-Filter (Venus-Filter) 2" (BPU2)
  • UV-IR Rejection Filter 1.25" (BPUVIR125) and 2" (BPUVIR2)
  • 50.8 mm Round, 3 mm Thick, Unmounted Narrowband Filters for STL Series CCD Cameras and other large format color filter wheels
  • Visual Narrowband O-III Filter - 1.25" (BPO3125) and 2" (BPO32)

    The non plus ultra for visual deep-sky observers, especially under extremely light-polluted skies. See planetary nebulae and supernova remnants come alive with the enhanced contrast from these filters.

    Among the narrowest transmission band O-III filters on the market, ideally suited for both visual use and for many imaging applications thanks to its unsurpassed contrast. No image degradation is perceptible even at the highest magnifications. Features the same ultra-hard, extremely durable vacuum-deposited dielectric coatings employed on the UHC-S filter.

    The Baader Visual O-III Filter effectively blocks the entire visual spectrum with the exception of the two closely paired emission lines from doubly ionized oxygen, eliminating the annoying colored halos surrounding stars that often appear through O-III filters manufactured by means of less sophisticated coating technology. We also offer two additional versions of this filter with extended infra-red blockage for many of today's IR sensitive CCD chips - in a 2" mounted and in a 50.8 mm unmounted configuration for the STL series of cameras.

    Transmission Curve - PDF document
    Extended Transmission Curve

    BPO3125$90.00 in stockAdd BPO3125 To My Cart
    BPO32$118.00 in stockAdd BPO32 To My Cart

    UHC-S High Transmission Nebula Filter - 1.25" (BPUHCS125) and 2" (BPUHCS2)

    A new generation of light pollution rejection/nebula filter. Baader Planetarium's unique “golden mean” design transmits sufficient light for even small aperture telescopes while preserving the high contrast of traditional UHC (Ultra High Contrast”) filters.

    Exactly tailored to block off all of the common streetlight emissions. The sensible alternative to all previous generations of Deep Sky and UHC filters both visually and photographically.

    Transmission Curve - PDF document
    Extended Transmission Curve

    BPUHCS125$85.00 Call Contact Astro-Physics about BPUHCS125
    BPUHCS2$114.00 in stockAdd BPUHCS2 To My Cart

    Color Filters - 1.25" (BPCF125) and 2" (BPCF2)

    These color filters provide the highest levels of image brightness and freedom from scattered light, combined with uncompromising image sharpness at the high magnifications required to observe delicate planetary details.

    All surfaces are polished to exacting tolerances of flatness and parallelism to far surpass the performance of "flame-polished" substrates employed in typical economy filters. All surfaces feature 7-layer multi-coatings that reduce reflective losses to a mere 0.25%.

    More Information
    Transmission Curve - PDF document
    Extended Transmission Curve

    BPCF125$174.00 in stockAdd BPCF125 To My Cart
    BPCF2$284.00 in stockAdd BPCF2 To My Cart


    Contrast-Booster Filter - 1.25" (BPCB125) and 2" (BPCB2)

    The ultimate contrast filter for all refractive optical systems. Eliminates color error of achromatic doublet objectives to provide the highest level of definition while correcting color balance. Surface details on the Moon and planets stand out boldly.

    You haven't really seen Jupiter's Great Red Spot though your achromatic refractor until you've used this filter.

    More Information - PDF document
    Transmission Curve - PDF document
    Extended Transmission Curve

    BPCB125$74.00 in stockAdd BPCB125 To My Cart
    BPCB2$115.00 in stockAdd BPCB2 To My Cart

    Neodymium ("Moonglow & Skyglow") Filter - 1.25" (BPMS125) and 2" (BPMS2)

    The Super Contrast Filter for all REFLECTOR and APO-TELESCOPES.

    This filter was designed to transmit the maximum amount of incoming light, while suppressing skyglow due to artificial lighting and background glow when the Moon is up. The filter material is a special Neodymium glass that effectively filters out selective wavelengths of low-pressure sodium and other manmade sources. Please note that this is NOT a moon filter, although it will enhance contrast in views of the moon. To dim the moon to a comfortable viewing brightness we recommend a neutral density filter which can be used to greater effect when combined with this Neodymium filter.

    More Information
    Transmission Curve - PDF document
    Extended Transmission Curve

    BPMS125$74.00 in stockAdd BPMS125 To My Cart
    BPMS2$119.00 in stockAdd BPMS2 To My Cart

    Semi-APO Filter - 2" (BPSAPO2)

    This Semi-APO filter, as with all Baader filters, is manufactured to the highest of optical standards and characteristics. It is optically flat and can be placed in front of the diagonal without deterioration of the image quality. Its spectral characteristics are similar to a combination of the Fringe-Killer and Moon & Skyglow filters with an increase in the ultraviolet rejection.

    Apart from its use with Achromats, it also serves as a wonderful planetary filter which enhances the contrast and viewable detail without distorting the color.

    Transmission Curve - PDF document

    BPSAPO2$137.00 in stockAdd BPSAPO2 To My Cart


    Neutral Density 1.8 Filter - 2" (BPND18)

    This 2" filter is threaded for 48 mm metric threads. It has a transmission rate of 1.6%, making it an ideal moon filter for large aperture instruments. Use this filter with the AstroSolar Density 3.8 Film for safe solar observation.

    IMPORTANT! Do not attempt to use this filter without a white-light filter in front of your main telescope optics. While it will supplement the ND 3.8 Photographic Density filter material to yield a safe combined transmission level, it is wholly insufficient by itself for solar viewing. Serious damage to your eyes could result from improper use of solar filters!

    BPND18$58.00 in stockAdd BPND18 To My Cart

    Polarizing Filter - 1.25" (BPPOL125) and 2" (BPPOL2)

    A polarizing filter is an excellent filter choice for lunar viewing. It provides variable neutral density (it darkens or lightens) as it is rotated, accomodating the different lunar stages. This filter is a single stage polarizing filter and must be used with a diagonal mirror, such as our MaxBright Diagonal (PMDMAX), to achieve the polarizing affect. This polarizer can similarly be used with the Herschel Prism (BPHERP) for solar viewing, but must always be used in addition to the ND3.0 filter (the ND3.0 filter must always remain in the Herschel Prism for viewing safety). When either lunar or solar viewing, the filter can be screwed onto the barrel of a 2" eyepiece or onto our 1.25" Eyepiece Adapter (ADA125). Note that in the case of our ADA125, you may need to add our 2" Barrel Extension (A3703) to accomodate 1.25" eyepieces with extra long barrels.

    BPPOL125$58.00 in stockAdd BPPOL125 To My Cart
    BPPOL2$87.00 in stockAdd BPPOL2 To My Cart


    Solar Continuum Filter - 1.25" (BPSC125) and 2" (BPSC2)

    Unsurpassed contrast of photospheric details is achieved by an extremely narrow half bandwidth of only 8nm. Functions like a monochrometer, suppressing the effects of atmospheric turbulence to provide images that appear markedly more stable.

    Focus "Sweet Spot Generator" - completely eliminates the usual focusing guesswork - the image snaps to a razor sharp focus at the exact focal position. Image the sun the way professionals do!

    IMPORTANT: The Solar Continuum Filter MUST be used in conjunction with a visual density white-light solar filter or Herschel Prism (with ND3.0 filter) in front of the lens. We suggest Astro-Solar ND 5.0 Visual Filter material, also from Baader Planetarium. DO NOT attempt to use this filter without a white-light filter in front of your main telescope optics. Serious damage to your eyes could result.

    Transmission Curve - PDF document
    Extended Transmission Curve

    BPSC125$88.00 in stockAdd BPSC125 To My Cart
    BPSC2$136.00 in stockAdd BPSC2 To My Cart

    H-Alpha Pass Filter - 2" (BPHA2)

    This is a 2" filter, threaded for 48mm metric threads. With a bandwidth of 35 nanometers, this filter is ideal for isolating H-II regions for excellent contrast in RGB CCD images. The wider bandwidth allows for more light through-put, while still enhancing the contrast of nebular features. Perfect for minimizing unwanted glow from light polluted skies in the red channel. The 2" filter size allows unvignetted imaging with large format CCD Cameras.

    Extended Transmission Curve

    BPHA2$170.00 in stockAdd BPHA2 To My Cart


    Narrowband Oxygen III Filter for CCD Imaging - 8.5 nm - 2" (BPO3285)

    This filter is the perfect companion to the 2" H-alpha pass filter shown above. It is an outstanding filter for CCD imagers because of its full 2" size, its narrow bandpass of 8.5 nm (full width at half maximum transmission), and its extended infra-red blockage well past 1000 nm. This filter is the 2" mounted version of the 50.8 mm OIII STL version shown below and has the same transmission characteristics. Although this would still make a great visual OIII filter, it is primarily directed at the CCD imager who needs the infra-red blockage. Visual observers should consider the standard Visual Narrowband O-III Filter which offers a slightly higher maximum transmission rate. Please note that the photos at left have been altered to present the teal color of the OIII emission line. Unless you are looking straight through the filter, the surface of the glass will more closely resemble a high quality mirror than a transparent color filter.

    Extended Transmission Curve

    BPO3285$200.00 in stockAdd BPO3285 To My Cart

    IR Pass Filter - 1.25" (BPIRP125) and 2" (BPIRP2)

    This filter finds application in planetary imaging. The passband begins in the deep red region at 670nm and extends well into the infrared. This long wave light can be used in IR LRGB imaging to produce a sharper luminance image for the best planetary contrast. Often the atmospheric seeing is much steadier at these IR wavelengths. Images taken with IR as luminance channel have produced some of the finest Mars pictures during the last opposition. Contrast on Jupiter and other planets is also visibly enhanced

    Both surfaces are optically polished to produce diffraction limited images and professionally coated to very tight tolerances.

    BPIRP125$82.00 in stockAdd BPIRP125 To My Cart
    BPIRP2$131.00 in stockAdd BPIRP2 To My Cart


    U-Filter (Venus-Filter) - 2" (BPU2)

    The Baader Venus filter blocks the entire spectral region from 200nm to 1500nm except for a very narrow bandwidth from 300nm to 400nm in the far violet. Transmission efficiency reaches 80% at the peak. This filter makes it possible to image cloud detail on the surface of Venus.

    Please Note: The Baader U-Filter is specifically for digital imaging (digital SLR, webcam or CCD). Since visual perception stops at about 400nm (380nm if you're lucky), the light transmitted through the filter is not detectable by the human eye. Do not purchase this filter for visual use! Also note that the colors in the photo at left are the true reflected colors of each side of the filter and are the result of the different dielectric coatings used on each surface.

    The accompanying photograph of Venus, taken by M. Rietze just 2 days before transit, shows the cusps enclosing two-thirds of the planet's circumference.

    Extended Transmission Curve

    BPU2$355.00 in stockAdd BPU2 To My Cart

    UV-IR Rejection Filter - 1.25" (BPUVIR125) and 2" (BPUVIR2)

    This filter is a must for all digital imaging with CCD cameras, digital cameras and webcams. Corresponds to the L ("Luminance") filter in an RGB filter set. Provides pinpoint stellar images.

    Reflects deleterious infrared rays without heating, while providing 98% transmission over the entire visual spectrum. The plane-parallel polished substrate allows this filter to be employed at large distances from the focal plane, notably in binocular viewers and for eyepiece projection.

    Exciting possibilities in combination with other filters! For example, when combined with the Solar Continuum Filter, the entire accessible electromagnetic spectrum is blocked with the exception of a narrow region around 540nm.

    More Information - PDF document
    Transmission Curve - PDF document

    BPUVIR125$66.00 in stockAdd BPUVIR125 To My Cart
    BPUVIR2$114.00 SeptemberAdd BPUVIR2 To My Cart



    H-alpha - pass


    H-alpha - 7nm


    OIII


    SII

    50.8 mm Round, 3 mm Thick, Unmounted, Narrowband, Imaging Filters for STL Series and other large CCD cameras

    These are the ultimate narrowband imaging filters for use with the STL series of large format CCD cameras from SBIG, as well as for use in color filter wheels by Finger Lakes Instruments, Apogee Instruments and others. They are unmounted (They have no filter cell.) so that they fit into the filter carousel with minimum vignetting. We carry these filters in four configurations. As with all of the Baader narrowband filters, the bandwidth specification is FWHM - Full Width at Half Maximum - the width of the transmission curve at a level equal to half the filter's maximum transmission rate. For more detailed technical information follow this link!

    • Hydrogen Alpha Pass Filter - 35 nm (BPHAPSTL)
      This filter with its wider bandpass allows more light through to the CCD chip in situations where the red band is not so heavily light polluted. It is often used for luminance in conjunction with RGB filter sets.
      BPHAPSTL$176.00 in stockAdd BPHAPSTL To My Cart

    • Hydrogen Alpha Narrowband Filter with extended IR blocking - 7 nm (BPNHASTL)
      This filter combines an extremely narrow transmission bandwidth around the 656.3 nm H-alpha emission line with infra-red blockage all the way out to 1200 nm!
      BPNHASTL$320.00 in stockAdd BPNHASTL To My Cart

    • Oxygen III Narrowband with extended IR blocking - 8.5 nm (BPNO3STL)
      The extremely popular Baader visual OIII filter has had its blockage extended into the infra-red for CCD imaging. Infra-red is effectively blocked out to 1050 nm while retaining the transmission performance around the closely paired emission lines of doubly ionized oxygen.
      BPNO3STL$246.00 in stockAdd BPNO3STL To My Cart

    • Sulfur II Narrowband with extended IR blocking - 8 nm (BPNS2STL)
      The deep red emission line of singly ionized sulfur is isolated by this narrowband filter. It effectively blocks infra-red radiation out past 1200 nm.
      BPNS2STL$255.00 in stockAdd BPNS2STL To My Cart

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    This page was last modified: April 1, 2014

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