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We now carry a large and growing selection of premium Baader Planetarium astronomical filters.  These filters are the result of many years of development and experience in the use and production of  optics using the very latest coating technologies.  Baader Planetarium filters incorporate features that result in performance and robustness not present in any other competing filter, yet at very reasonable prices.  Please read through the detail below, and see why these filters are so special.


Planetary and Contrast

 >  Baader Semi-APO   (1 and NEW  2")

 >  Baader Fringe Killer   (1  and 2")

  Baader Contrast-Booster  (1 and 2")

 >  Baader Moon & Skyglow Planetary Contrast Enhancement Filter  (1 and 2")

 >  Baader Colored Filters  (1 and 2")

 >  Baader Solar Continuum  Filter  (1 and 2")   

Deep Sky

 >  Baader UHC-S Nebula Filter   (1 and 2" )   

 >  Baader O-III Nebula Filter   (1 and 2" )   

Imaging Filters

 >  Baader UV-IR-Cut Filter  (1,2"), and

 >  Canon EOS DSLR Filters  (Canon 300D/350D/5D/10D/20D/30D/40D/4000D/Xti/450D, 50D/500D/550D/600D/1000D/1100D/Rebel XS/T1i/T2i/T3/T3i)  

 >  Baader IR-Pass Filter  (1 and 2")   

 >  Baader Venus U-Filter  (1 and 2")     

 >  Baader MidBand 35nm H-Alpha Filter  (2")   

 >  Baader Narrowband CCD H-Alpha, O-III, H-Beta, S-II Filters  (1.25", 2", 50.8mm Round, Square 50/65mm)

  Baader f/2 Highspeed CCD Filters: H-Alpha, O-III, S-II  (1.25", 2", STL) NEW

 >  Baader 3.5nm Narrowband H-Alpha Filters  (2", 50.8mm Round,, Square 50mm) NEW

 >  Baader LRGBC Filters  (1.25", 2", 50.8mm Round, 50mm Square) 

 >  2" DSLR Filter Adapter  



Why Baader Planetarium Filters?

  • True Optical Quality:  Baader glass substrates are of true optical quality.  Most other filters are merely made from raw flame-polished, "optically flat", or sometimes use a top quality commercially polished filter glass (fine for camera filters), resulting in wavefront deformations that damage image sharpness and contrast when used with telescopes.  Baader Planetarium filters are made from striae-free substrates, and actually fineoptically polished flat to within 1/4 wave p-v over the entire surface, plane parallel to within 30 seconds of arc!  This important and unique custom step adds cost - but the result is a filter that maintains the full wavefront quality of the telescope without double images or ghosting, even at high magnifications.   Critical to maintaining this level of flatness are Baader's carefully balanced coating designs, which prevent coating surface stresses from warping the substrate.   Such high flatness enables Baader filters to be used far in front of the focal plane, ahead of star diagonals, and digital cameras.  They are particularly well suited for attachment to the nosepiece of the Maxbright Binocular-Viewer (other manufacturer's filters must be used in pairs, attached right at the eyepieces).

  • Filter Durability:  Filter durability has always been a hallmark of Baader Planetarium.  The multi-layer dielectric coatings are plasma assisted and Ionbeam hardened using the latest technology (the coatings are harder than the glass substrate itself!).  Baader filters withstand repeated real-world exposure to the elements and physical cleaning.  Users need not leave their precious filters dull and dust encrusted to avoid cleaning - Baader filters may be used and cleaned without fear.  We have heard sad stories from owners of other less durable filters, who have seen their coatings degrade from normal exposure to moisture, or wiped away from routine cleaning.  Some manufacturers of astro filters resort to coating large sheets of bulk glass, then literally cutting or breaking their filters from the precoated sheets, ripping and tearing the coating's edges in the process - leaving the edges susceptible to moisture penetration and coating peel.  This literal shortcut gives a manufacturer the ability to reduce stock and easily produce filters on demand or to readily produce odd sizes, but it comes at the expense of the customer by producing an inferior filter with greater risk of coating failure.  Other filters are produced by sandwiching their delicate coatings in between two layers of glass (and risking blurred double images as well as eventual degradation from the edges inward).  Baader Filters will truly last lifetimes.  Though we don't recommend trying this yourself, Baader filters have passed rigorous military durability tests that subject the filters to boiling water for several hours, then comparing spectral traces before and after.  The Baader filters pass this test with no coating degradation.

  • Freedom from Ghosts and Halos:  Baader Planetarium's filters have always been halo and ghost free.  Baader balances each dielectric coating stack to avoid the ghosts and annoying halos that plague other mfgr's filters. 

  • Stackability:  Unlike most other filters, Baader Planetarium  filters are truly designed to be stacked and combined.  This is possible due to the high optical quality and highly efficient anti-reflection multicoatings.  The ability to combine filters opens up many interesting possibilities, permitting  unique spectral characteristics unachievable with any single filter. 

  • Special Filter Cell:  Baader's special filter cell design offers unique features that enhance their reliability and usability.  Though difficult to produce, the ultra-thin filter cell results in the maximum possible clear aperture, in order to minimize vignetting (1" Filter clear aperture is 27mm!, 2" Filter aperture is 45mm).  The special threading has been designed to fit the wide variety of eyepieces and accessories (there is significant variation between the 1 filter threading used by eyepiece and accessory manufacturers).  The front 'crown' of the filter incorporates milled notches which make handling and threading the filter a more secure operation in the dark. 

  • Low cost:  It has always surprised us to see the exhorbitantly high prices for some 'premium' filters offered by other manufacturers.   Evidently, these prices endure due to misperception that higher prices imply higher quality or discernable higher performance.   Fortunately, that perception is absolutely false.  Despite the highest optical and coating quality in the industry, and use of  leading edge German coating technologies, Baader Planetarium filters remain affordable for the amateur.   By leveraging high volumes across all filters in the Baader family, these filters can be offered at very reasonable prices (and with a clear conscience...).  


For further detailed information on Baader's Unique filters and cells, please click on the following image:



(332KB pdf file)



Baader Semi-APO



Baader's newest addition for Achromat owners. The Semi-APO works like it's name implies - delivering an amazingly neutral view, while cutting most of the annoying and contrast-robbing violet fringe that plagues all achromats. The Semi-APO filter combines a stronger Fringe Killer coating formula with the Moon&Skyglow Neodymium substrate.  The result is similar performance to the Fringe Killer + Moon&Skyglow combination, but with a slightly stronger violet cut  - and at an even greater $$ value.

The Semi-APO filter benefits from all the host of world-class Baader filter attributes.  The Semi-APO filter is truly the world's most advanced 'minus-violet' type filter in every regard.  It's high efficiency and neutral coloration make it practically disappear in use - while making most of the violet fringe disappear!  The effects on sharpness, contrast, and aesthetics are remarkable, even with small refractors.  The RGB enhancement of the Neodymium substrate actually boosts color contrasts, particularly for Jupiter and Mars. 

As a side benefit, the Semi-APO filter has also proven to be the best Mars filter we've used - with ALL Telescopes, including large Dobsonians, SCTs, and Apochromats.   The unique properties that result from the combination of the Fringe Killer's blue wavelength attenuation (attenuation  - not total elimination), plus the selective Neodymium RGB passbands, result in a significant contrast enhancement of Martian features.  The image retains its natural coloration and brightness, and the optically polished surfaces maintain every bit of the image sharpness, unlike other manufacturer's filters.

The high quality of Baader Planetarium filters permits their use well ahead of the focal plane with no image degradation (ie, for cameras or binoviewers).   The inclusion of Baader's renowned UV/IR Cut coatings on the Semi-APO eliminate UV and IR wavelengths to make it ideal for high-resolution imaging with Webcams, DSLR, and CCD cameras (see the UV/IR Cut  filter below, for more detail on these coatings).  The high transmission and fringe reduction work great for both planetary and deep sky imaging.

Please refer to the Fringe Killer and Moon&Skyglow for further detail on all of the other aspects of the Semi-APO filter.

- Baader Semi-APO,  1  (#FSAPO-1)

- Baader Semi-APO,  2  (#FSAPO-2)  NEW!



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Baader Fringe Killer


* As Reviewed in the April 2004 Sky and telescope *

Achromat owners rejoice!  Baader Planetarium has taken  minus violet filtration to a new level.  The Fringe Killer brings a type of filtration, never before seen, to the amateur.  Rather than simply trimming the shorter wavelengths at a chosen wavelength and slope like all other minus violet filters, the Fringe Killer carefully attenuates a specific region of the spectrum.  This allowed Baader to tune the filter for maximum practical reduction of the most damaging defocused blue wavelengths, with only a faint yellow color shift - without dimming and lowering image contrast by resorting to reduction of the  important green-yellow wavelengths to crudely restore an apparent color balance!  (where the eye is very sensitive, and where refractors are their sharpest)  The result is a filter that removes the majority of color fringe, without  affecting image brightness all, imparting strong coloration, or reducing contrast at  important wavelengths.   As any telescope owner knows, light is a valuable commodity for both planetary and deep sky viewing, and the fringe killer preserves every bit of light possible.  Terrestrial observers will also find the qualities of this filter to be ideal for their needs.

The high quality of Baader Planetarium filters permits stacking with no image degradation.  For an even less colored view, with noticeably boosted color contrasts, we highly recommend stacking a Moon & Skyglow  filter with the Fringe Killer.  These two filters compliment each other, and the result is an almost totally neutral view (no coloration).   Image brightness is also very minimally affected, due to the optimized formula of the Moon & Skyglow, along with the superb anti reflection coatings.

For two recent user reviews of the Fringe Killer, please see Cloudy Nights at:

and Mike Swanson's NexStar Site at:

The Fringe Killer is the perfect compliment to the Baader Contrast Booster.  The Contrast Booster is an aggressive filter, designed to deliver the maximum sharpness and contrast possible from an achromat.  The result is complete removal of the violet haze, with a somewhat dimmer and yellowier image.  The Contrast Booster also incorporates additional RGB filtration for further enhancing color contrasts.  The Fringe Killer provides a milder more natural filtration, that leaves fast achromats performing much like a classical f/15 achromat.  The Fringe Killer delivers what we feel is an ideal combination of improved resolution, contrast and unaltered  image brightness, along with a very aesthetically pleasing view. 

The coatings required to accomplish this innovative filtration are exceedingly complex, requiring almost 50 layers per side, using the latest DWDM Plasma assisted coating process.   The Fringe Killer has perhaps the most complex coating ever achieved on an amateur astronomical filter

Digital Imagers (CCD, DigiCam, and Webcam) will find the Fringe Killer to be the ultimate mate for their achromatic refractor.  The high transmission and fringe reduction work great for both planetary and deep sky imaging.  Baader has also chosen to include their renowned UV/IR Cut coatings as part of the Fringe Killer formula.  These coatings maintain very high transmission, with well placed sharp cutoffs in the IR and UV (see the UV/IR Cut  filter below, for more detail on these coatings).

Just like all the other Baader Planetarium filters, the Fringe Killer offers their trademark high quality and features.  The result is industry leading performance and value.

For more information on this filter, including spectral curves, please click on the PDF link below:

Fringe Killer Data Sheet (782 kB!)

Photo of fringe killer held over a sheet of paper in natural sunlight, illustrating the high transmission and low coloration.


- Baader Fringe Killer,  1  (#FFK-1)


- Baader Fringe Killer,  2  (#FFK-2)



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Baader Contrast-Booster


Much more than a simple minus-violet filter.  Based on the popular Baader Moon&Skyglow filter, the Baader Contrast-Booster takes contrast enhancement and skyglow reduction to the maximum level possible from a filter.  Not only does this filter deliver a significant enhancement of planetary and lunar contrasts, but it is designed to also totally eliminate the damaging blue defocused haze present in achromatic refractors.  Gone are the annoying blue halo and obscuring haze that surround and smear resolution and contrast.  Subtle contrasts and colors are boosted, while displaying the full resolution your scope is capable of. 

The Contrast-Booster combines a special proprietary melt of Neodymium glass with a carefully designed 23 layer dielectric long-pass blocker on one face, and a 7-layer ultra-low antireflection coating on the other face.  By aggressively filtering out the defocused blue wavelengths, a light yellow tint is imparted to objects (noticeably less than a typical yellow filter).  The special coatings enable over 95% transmission across key portions of the visible spectrum (including H-Alpha). This results in a filter that retains the colors and color contrasts in tough subjects like Jupiter, without excessive image dimming.  Cloud bands retain their ruddy red hues, but now become more striking in contrast.  The Great Red Spot finally becomes easier.  Planets and Lunarscapes are set against a jet black sky.  The Contrast-Booster is a must for Solar observing (with Baader Astro Solar). 

As many users have found, this is a great filter for Mars!  The views of Mars with all telescopes (including reflectors and apochromats) benefit from the RGB filtration plus blue blocking.

Combined with the Baader UV-IR-Cut Filter, the Contrast-Booster makes the ideal filter set for digital imaging.  Rather than add the cost of additional IR filtration (only needed for digital imaging), the Baader Contrast Booster has been optimized for visual use.  Digital imagers can simply add our Baader UV-IR-Cut Filter when needed.  The true 1/4 wave fineoptically polished surfaces guarantee the sharpness and contrast of the image.  Filters are available in both 1 and 2" sizes.

The base substrate is a special custom melt of Neodymium doped glass, designed for specific transmission characteristics, and made only for Baader Planetarium.  In addition to it's unique spectral characteristics, the Contrast-Booster offers Baader's hallmark optical and mechanical features that set it apart and result in the best possible image sharpness, contrast, and real-world durability;

"The contrast booster filter certainly removes the violet glow from my 6" f/8 refractor both on the bright stars and the moon.  It does give a "warm" yellow tint to both.  I soon got used to this when observing the moon and it posed no problem.  I tried it on Mars.  Unfortunately I am too far north(+53deg) to escape the worst effects of the earths atmosphere and seeing varied from fair to terrible.  Still, it did make the dark markings more clearly visible.  The quality of the glass is superb.  Some other filters I have used cause a softening of the detail; not so with the Baader.  All in all a very worthwhile addition to my observing tools; and at a great price too."  Pat Abbott

"Just wanted to let you know that the Baader Contrast Booster Filter is a GREAT product. Far and away the single best filter that I have used on Mars. I'm looking forward to Jupiter and Saturn. It also really helped with my webcam imaging of Mars."  Gordon Dayton

For more information on this filter, including transmission curve, please click on the More Info link below.

- Baader Contrast-Booster,  1  (#FCB-1)

- Baader Contrast-Booster, 2"   (#FCB-2)



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Baader Moon & Skyglow Filter


The Baader Planetarium Moon & Skyglow (Neodymium) filter brings an entirely unique approach to planetary contrast enhancement and light pollution reduction.  Based on earlier research at Carl Zeiss, Baader has developed a new filter that uses  Neodymium glass which filters out a few specific wavelengths from streetlights as well as skyglow from the Moon.  The unique spectral characteristics of Neodymium also boost color contrasts by isolating  the Red, Green, and Blue regions (so-called RGB enhancement).  The result is a filter that leaves natural colors mostly intact, but significantly enhanced.

Planetary and Lunar views are improved in all scopes, reflectors, refractors (APO or Achro).  Jupiter's Great Red Spot and ruddy hues of the bands are noticeably enhanced, and contrast of Martian surface features significantly boosted.  The Background sky is darkened, and subtle details improved.  The filter's high efficiency preserves image brightness, and many Galaxies, Nebulae and Globular Star Clusters are improved due to the reduction of skyglow from artificial lighting.   For a hands-on review of the Moon & Skyglow Filter, visit the accessories review section at

The high quality of Baader Planetarium filters permits stacking with no image degradation.  Achromat owners will find the combination of Moon & Skyglow and the new Fringe Killer filter to be ideal for planetary viewing.  The high light throughput and natural coloration will make achromats perform more like an apochromat.  An integrated version is also now available, the Semi-APO filter.

The Moon & Skyglow is also optimized for imagers, due to its full IR-blocking (See the filter curve on the datasheet  included in the link, below).

The filter substrate is a special custom melt of Neodymium doped glass, designed for specific transmission characteristics, and made only for Baader Planetarium.  In addition to it's unique spectral characteristics, unlike most filters, the Baader Moon & Skyglow surfaces are optically polished to deliver the best possible image sharpness and contrast. 

The images below demonstrate the large contrast improvement on Mars.  The image on the left was taken without filtration, while the image on the right was taken  through a Moon & Skyglow.  The Moon & Skyglow image shows significantly higher contrast and surface features barely visible without the filter.    Both images were acquired identically, without any contrast enhancement, and give a very good idea of the planetary contrast improvement that is seen visually.  The Moon & Skyglow never leaves our own telescopes when observing the planets and moon.

Image courtesy of Jeremy Summers.  Taken in Nov. 05  with a Meade LXD55 8" SCT and Canon A510 digital camera in video mode

(raw images stacked with Registax, no processing to either image).

For more information on this filter, including transmission curve, please click on the PDF link below:

Moon and Skyglow Filter Data Sheet (351kB)

- Baader Moon & Skyglow Filter,  1  (#FMS-1)

- Baader Moon & Skyglow Filter, 2"   (#FMS-2)



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Baader Premium Colored Filters


NOW in 2" SIZE!

Not just another colored filter.  Finally, a set of serious tools for the planetary observer.  Baader Planetarium's Premium Colored Filters bring a new level of quality and performance to planetary contrast enhancement.   Available singly, or as a full set of 6 filters in both 1 and 2" Sizes.

  • Freedom from Ghost images, even when stacked.  Striae-free substrates are polished parallel to 30 seconds of to avoid wedge errors.  Finest 7-layer  hard multicoatings on both faces feature 0.25% residual reflections (Baader filters are unique, no other colored filter incorporates anti-reflection multicoatings).  The coatings are also different for each of the filters, in order to match the coating performance to the filter curve of each color.  This maximizes the transmission and minimizes reflections.

  •  Extremely High Transmissions result in maximum contrast and isolation of planetary details, even with smaller telescopes.  Efficiencies of the three longpass filters (Red, Orange, and Yellow) peaks at 98%, and efficiencies of the three bandpass filters (Green, Blue, Dark Blue) achieve 70%. 

  • Carefully designed spectral characteristics.  Filters may be stacked without image degradation or ghosting, in order to provide even narrower passbands.  Or, combine with any of the other Baader filters for interesting possibilities.  For actual spectral traces, see Color Filter Transmission Curves.

  • No reduction in sharpness, even at high magnifications or when using the filter far ahead of the focal plane (ie, digital imaging, or in front of a diagonal or binoviewer). 

  • With the new 2" size, only one filter is needed for binoviewing.  Only Baader colored filters have the optical quality necessary for use this far ahead of the focal plane.

For  a data sheet containing more information on these filters, including transmission curves, please click on the MORE INFO link (344kb pdf).

- Set of all 6 Premium Colored Filters, 1  (#FCFS-1), 2  (#FCFS-2)

- Red (610 nm) Longpass, 1  (#FCFR-1), 2  (#FCFR-2)

- Orange (570 nm) Longpass, 1  (#FCFO-1), 2  (#FCFO-2)

- Yellow (495 nm) Longpass, 1  (#FCFY-1), 2  (#FCFY-2)

- Green (500 nm) Bandpass, 1  (#FCFG-1), 2  (#FCFG-2)

- Bright Blue (470 nm) Bandpass, 1  (#FCFB-1), 2  (#FCFB-2)

- Dark Blue (435 nm) Bandpass, 1  (#FCFDB-1), 2  (#FCFDB-2)



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Baader UHC-S Nebula Filter


The Baader Planetarium UHC-S Nebula filter excels at delivering a high-contrast and natural view of emission nebula - without excessive dimming and loss of background star fields.  The perfect filter for viewing emission nebula from light polluted skies, or for boosting the contrast of nebula from dark sky sites.  The advanced technology coatings enable the filter to achieve an outstanding transmission of over 97% across the entire passband, with total blockage of prominent light pollution lines.  This translates to maximum image brightness and contrast.  Owners of smaller, 4"-10" telescopes will especially appreciate the high efficiency, and larger scope users will love the rich star fields and detailed subtle nebular shadings that are left intact.

The Baader UHC-S manages to improve on the contrast of the typical broadband or so-called "Deep Sky" filters.  Sky background is darker, and contrast of emission nebulae are noticeably improved.   Most other "UHC" filters tend to excessively darken the sky and star fields, leaving the nebulae looking artificial and flat, set against an empty background.  The high transmission, sharp cutoffs, and more moderate 60nm passband of the Baader UHC-S filter retains a more natural view, yet significantly boosts overall contrast.  Imagers will appreciate the broader passband and inclusion of an extremely efficient H-Alpha passband  (>99% @656nm), as well as the extreme optical quality.

At the heart of the Baader UHC-S filters are their special fineoptical substrate polishing process and  advanced coating design.  The result is a filter that imparts no image degradation, unlike other filters.  To prevent deterioration from cleaning or exposure to moisture, some other filters even resort to sandwiching their delicate coatings between two layers of filter glass, resulting in potential blurred or double images.  The combination of hardened coatings and fineoptical substrate of the Baader UHC-S avoids this image degradation.  A common misperception is that deep sky viewing is limited to low powers, and image resolution is not as important as in planetary observation.  In reality, high magnifications are very common and useful in studying fine details, particularly for the brighter diffuse and planetary nebulae.  Baader UHC-S filters can take high magnifications, and stars retain their pinpoint sharpness, even if the filter is used far ahead of the image plane (ie, for imaging use, or ahead of a star diagonal or binoviewer).  Baader filters fulfill the requirements of an ideal filter - to perform their filtration at highest efficiency without any other detectable effect on the image.

Please click on the image below for a typical transmission curve:

UHC-S Filter Transmission Curve



- Baader UHC-S Nebula Filter,  1  (#FUHC-1)

- Baader UHC-S Nebula Filter, 2"   (#FUHC-2)



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Baader O-III Visual Nebula Filter


Delivers the absolute highest contrast views of many diffuse and planetary nebula.   For many objects, the Baader O-III reveals a level of intricate detail that rivals the best deep sky photographs.   Our favorite filter for the majority of nebula, especially The Veil, Lagoon (M8), Swan (M17), Ring (M57) and Dumbell (M29).  With a large scope, you can even view the famous 'Pillars of Creation' in M16 (Eagle).

The Baader O-III perfectly isolates the two doubly ionized oxygen lines (496 and 501nm), through a very sharp and optimally narrow bandpass (10 nm wide).   Unlike other O-III filters, the Baader O-III completely blocks longer and shorter wavelengths (ever wonder why some O-III filters appear RED?, instead of the correct 500 nm Teal color).  The result is the highest contrast achievable in an O-III filter.

The O-III benefits from the precision fineoptically polished flat substrate, and advanced DWDM plasma assisted coatings.  As a result, the Baader O-III will not degrade image sharpness or impart double images.  To prevent deterioration from cleaning or exposure to moisture, some other filters even resort to sandwiching their delicate coatings between two layers of filter glass, resulting in potential blurred or double images.   Contrary to myth, nebula filters are often useful at high magnifications, where image quality counts.  Baader O-III filters can take high magnifications, and stars retain their pinpoint sharpness, even if the filter is used far ahead of the image plane (ie, for imaging use, or ahead of a star diagonal or binoviewer).   Combine with our UV/IR filter for the ultimate in O-III deep sky imaging.

Please click on the image below for a typical transmission curve:

O-III Filter Transmission Curve



- Baader O-III Nebula Filter,  1  (#FO-III-1)

- Baader O-III Nebula Filter, 2"   (#FO-III-2)



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Baader UV-IR-Cut Filters


1 Filter

2 Filter

Baader Planetarium has introduced the world's finest UV/IR cut filter.  This filter is a must for all digital imaging with Digital Cameras, CCD Cameras, and modified WebCams.  Also useful for protecting valuable H-Alpha filters from heat stress and damaging IR (Daystar, etc).  Due to their extremely high optical quality, these filters may be stacked and used far in front of the focal plane (necessary for imaging uses).  Like the Baader Planetarium Contrast-Booster, the UV-IR-Cut filter uses the very latest coating technology, to deliver the finest filtration quality - and lifetime durability.


  • Unmatched 98% Average Transmission!  Freedom from ghost images (very low reflection multi-coating, Striae-free, and plane-parallel substrate).
  • Extremely Sharp Cutoff at 680nm  (leaves all the visible red, including the important 656nm H-alpha emission line).
  • Sharp cutoff below 420nm.  Eliminates violet halos around bright stars (more effectively than simpler so-called Minus Violet photographic filters).
  • True optical quality glass substrate and coatings. Why spend all your money on quality primary optics - only to place a lower grade filter optic in the path?
  • Combine with any of the other Baader filters, to deliver the sharpest images possible.

"Got the uv-ir-cut filter.  Mounted it internally inside a 400mm lens that I glued to a cheap 3.2 MP camera WORKS GREAT!!  Better than the hot mirror supplied with camera more red channel more light - higher shutter speed.  At least one extra stop."  Luke Gale


- Baader UV-IR-Cut, 1  (#FUVIR-1)

- Baader UV-IR-Cut, 2"   (#FUVIR-2)

- Baader UV-IR-Cut, 50.8mm Round   (#FUVIR-RND)

- Baader UV-IR-Cut, 50mm Square (3mm Thick)  (#FUVIR-SQ)




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Baader Astro Conversion Filters for CANON DSLRs

Factory Filter (Top)

FACF-II (Bottom)

DSLR Conversion Filters for Canon EOS cameras.  Turn your Canon DSLR into a superb deep sky AstroCamera.  Baader's DSLR conversion filters replace the factory correcting filter ("hot mirror").  The special substrate is coated with Baader's renowned coatings.  Imagers can now gain  full efficiency at H-Alpha wavelengths, and at full resolution (the Baader filter eliminates the Canon factory moire filter, which reduces resolution on astronomical subjects).  The thickness of the Baader DSLR filters have been designed to maintain the correct factory focal point (please note:  The Baader filter is intentionally of a different thickness than the factory filter - this is required to match the effective index of refraction of the factory 'sandwich' filter). 

The Baader DSLR Conversion Filters are produced to the same specifications and by the same processes used for all of their other premium Baader Astronomical Filters.  Each filter is optically polished to 1/4 wave and most importantly the ionbeam hardened coatings are applied AFTER cutting and polishing.  This important aspect guarantees that your coatings will not peel or degrade due to the softer coatings and edge damage caused by post-cutting operations used by some other filters to cut costs.  With a Baader filter, you never need to worry that your internal DSLR Conversion filter will fail prematurely.  

This filter is intended for amateurs that are comfortable replacing their camera's stock filter.  Please Note:  For best performance we recommend installing the filter with the coated (pinkish) side facing out (FACF-1, II, III).  The FBCF-400D is clear with no pinkish side and does not require any particular orientation.  The digital astro eGroup is a great place for advice on how to replace this filter.  Here are links to some very well done filter replacement websites:

If you are uncomfortable doing the replacement yourself, here are two reasonably priced replacement services that use genuine Baader DSLR Filters and are very experienced at filter replacement:

Here's a nice tutorial on retrofitting a Canon 450D with the FBCF-400D:

Here's a very nice YouTube video done by Gary Honis on retrofitting a Canon 450D with the FBCF-400D:

For more information, including transmission curve, please click on the More Info link below.

- Baader DSLR Filters, Replacement Filters for Canon DSLRs

(#FACF-1 for Canon 300D, #FACF-2 for 350D/10D/20D/30D, #FBCF-400D for new EOS 7D/40D/50D/60D/ 400D/450D/500D/550D/600D/650D/1000D/1100D/Rebel XS/T1i/T2i/T3/T3K,T4i,  FBCF-5DII for the new 5D MkII)




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Baader IR-Pass Filter


Baader Planetarium delivers the latest tool in the planetary imager's bag of tricks.  The Baader IR-Pass filter blocks wavelengths below  670 nm.  At these longer wavelengths, planetary images are less disturbed by wavefront distortions in the atmosphere (seeing).  By combining a luminance image taken with the IR-Pass filter, along with  RGB frames, overall image sharpness is significantly enhanced.  Some of the world's best amateur planetary images have been taken with this technique.

Also darkens the twilight sky background, allowing mages of moon and planets to be taken at dawn or dusk.  Deep sky images reveal young hot stars in dust clouds and star forming regions.

The IR-Pass filter shares the same outstanding features as all the other Baader filters.  High optical quality, Striae-free substrate, and high efficiency multicoatings result in the sharpest and highest contrast image possible.

In addtion to astronomical uses, theIR-Pass filter can be used for nature photography in the Near-IR, revealing stunning differences in plants, sky, and clouds (requires use of a camera that is sensitive to IR above 670nm, such as a modified DSLR or webcam).  

Please click on the image below for a typical transmission curve:

IR-Pass Filter Transmission Curve



- Baader IR-Pass Filter,  1  (#FIRP-1)

- Baader IR-Pass Filter, 2"   (#FIRP-2)



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Baader Venus U-Filter ♦ 


Another unique and pioneering filter from Baader Planetarium.  For the first time, amateurs can now record cloud structures on Venus.  The Baader Venus Filter enables amateurs to successfully image in the deep UV, a spectral region normally inaccessible. 

The latest coating technologies permit the Baader Venus Filter to transmit from 300nm to 400nm, with a peak transmission of 80%.  The filter completely blocks the rest of the region from 200nm to 1500nm, through the use of a complex 20 layer dielectric coating stack, on top of a special optically polished UG-11 substrate.  Up till now, Amateur efforts typically relied upon deep violet colored filters, or combinations with simpler interference filters, which do not provide the high transmission and efficient rejection outside the important spectral region from 320nm to 390nm.   Given the poor transmissions of many optics in the UV and the lower sensitivity of some CCDs to this wavelength, high filter efficiency and complete rejection at longer wavelengths becomes paramount to recording good contrast at reasonable exposures.  The same high optical quality and features as the other Baader filters ensures the highest contrast and sharpest images possible.

Interestingly, the solar Calcium K-Line is also within the pass band of this filter.  This opens up the exciting possibility for recording flare structures on the solar disk or edges. 

The Baader U Filter has become the choice of UV imagers exploring the UV world of landscape, floral, and even forensic imaging.  The latest 2" filter now has even higher transmission and improved out of band blocking.  By using our DSLR-2 filter adapter ring plus the appropriate filter step ring (HDT-Rings), UV imagers can conveniently mount the U-Filter to their camera lens.

Here are some useful and interesting UV  sites with some nice images of flowers and information on UV imaging.  From there you can also link to many other UV sites:

Please Note:  The Baader Venus filter is only applicable for imaging of Venus with Webcam, Digital, and CCD cameras (Visual Observation is impossible, due to the eye's insensitivity to the UV).  For successful Venus imaging, we recommend the use of a UV sensitive astro CCD camera (ie, SBIG ST-2000XM) and at least a 5" telescope, or a webcam and 8" telescope.

Please click on the image below for a typical transmission curve:

Venus Filter Transmission Curve



- Baader Venus Filter,  1.25  (#FUV-1)  NEW

- Baader Venus Filter,  2  (#FUV-2) 



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Baader MidBand H-Alpha Filter


Baader's new H-Alpha passfilter enables high-contrast deep sky images of H-II regions (such as the N. American Nebula).  Its medium 35nm FWHM bandwidth is ideal for interline CCD cameras ( like SBIG ST-2000/STL11000). The lower sensitivity of interline transfer CCDs benefits from the more efficient 35nm FWHM.  The sharp bandpass and > 90% high efficiency coatings make the Baader H-Alpha filter superior to the common colored-glass based filters, all at a reasonable price.

The Baader H-Alpha filter shares the same outstanding features as all the other Baader imaging filters.  Unmatched optical quality, and high efficiency hardened multicoatings result in the sharpest and highest contrast images possible.

Please click on the image below for a typical transmission curve:

H-Alpha Transmission Curve



- Baader H-Alpha CCD Filter 35nm, 2"   (#FHAL-2)



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 Baader Premium Narrowband CCD Filters


CCD imagers will find Baader's Premium Narrowband CCD passfilters to deliver the absolute highest contrast deep sky images in H-Alpha, H-Beta, Oxygen III, and Sulfur-II, with the shortest exposures possible.  Their ultra-narrow bandwidths have extremely high transmissions, while completely rejecting light pollution as well as the important blocking of longer wavelengths.

The high optical quality of the Baader narrowband filters guarantees no loss in sharpness or contrast.  Each substrate is fine-optically polished plane parallel to deliver a smooth and accurate 1/4 wavefront over the entire surface.  This special custom polishing operation sets Baader filters apart from the standard commercially precision polished filter substrates used by most other filter manufacturers. 

In addition to their transmission properties, the Baader coatings were developed with another key goal in mind - eliminate the annoying reflections present in other narrowband astro-filters.  To achieve this freedom from reflections, along with excellent out of band blocking, required careful design and testing of the coating stacks.

Coatings are professionally applied in Germany by the most sophisticated equipment available today, ensuring high consistency for bandpass centering, transmission, and out of band blocking.  The anti-reflection coatings are designed to prevent halos and balanced to prevent physical deformation of the optically flat substrates. The ultra-hard ionbeam deposition ensures the coatings will never degrade from use or normal cleaning.   Each filter is coated individually, permanently sealing the coating edges, in order to guarantee lifetime coating durability and uniformity.  Baader mil-spec coatings won't degrade, peel or flake off, unlike the coatings of filters that have been simply cut out of pre-coated sheets of glass.  This cutting operation leaves the coating edges rough and torn which enables penetration of moisture between the coatings and substrate.

These filters are available in three sizes, standard 1", 2", and a 50.8mm diameter bare substrate (unmounted) for use in SBIG STL cameras.   A new unmounted 50mm square version of the H-a filter is now available for large format cameras (H-b, O-III, and S-II 50mm Square filters are due in late summer of 2009).  Clear parfocal filters are also available to assist in focusing.

Click on the images below for typical transmission curves:

H-Alpha Transmission Curve

H-Beta Transmission Curve

O-III Transmission Curve

S-II Transmission Curve






H-alpha Spectrogram

(transmission of solar spectrum)

H-beta Spectrogram

(transmission of solar spectrum)

O-III Spectrogram

(transmission of solar spectrum)

S-II Spectrogram

(transmission of solar spectrum)



NGC7000+Pelican Mosaic taken with Baader Narrowband CCD filters.  Note the tight stars and absence of halos.  Image courtesy of Johannes Schedler 2008 by Panther Observatory.




Please click on the thumbnail below for an image taken through the Baader Narrowband 7nm H-Alpha filter.  This image was taken with a TEC-140 @f/7 using an SBIG ST-10XE.  Total exposure of 280 minutes (14 x 20).  This image was taken from suburban Boston with a full moon 40degrees away!


Image Courtesy of John Boudreau



NOTE for Users of the Unmounted Filters (RND and SQ):  The preferred oriention of the filter is to have the highest reflectivity side facing skyward. 


Individual Filters

- Baader Narrowband 7nm H-Alpha Filter, 1"   (#FHALN-1)

- Baader Narrowband 7nm H-Alpha Filter, 2"   (#FHALN-2)

- Baader Narrowband 7nm H-Alpha Filter, 50.8mm Dia Unmounted   (#FHALN-RND)

- Baader Narrowband 7nm H-Alpha Filter, 50x50x3mm Square Unmounted   (#FHALN-SQ)

- Baader Narrowband 8.5nm H-Beta Filter, 1"   (#FHBN-1)

- Baader Narrowband 8.5nm H-Beta Filter, 2"   (#FHBN-2)

- Baader Narrowband 8.5nm H-Beta Filter, 50.8mm   (#FHBN-RND)

- Baader Narrowband 8.5nm O-III Filter, 1"   (#FOIIIN-1)

- Baader Narrowband 8.5nm O-III Filter, 2"   (#FOIIIN-2)

- Baader Narrowband 8.5nm O-III Filter, 50.8mm   (#FOIIIN-RND)

- Baader Narrowband 8nm S-II Filter, 1"   (#FSIIN-1)

- Baader Narrowband 8nm S-II Filter, 2"   (#FSIIN-2)

- Baader Narrowband 8nm S-II Filter, 50.8mm   (#FSIIN-RND)


Filter Sets

- Set of 3 Narrowband Filters (H-a/O-III/S-II): 1" (FNSET3-1), 2" (FNSET3-2),

  50.8mm Dia Unmounted (FNS3-RND), 50x50x3mm Square Unmounted (FNSET3-SQ)

- Set of 4 Narrowband Filters (H-a/H-b/O-III/S-II): 1" (FNSET4-1), 2" (FNSET4-2),

  50.8mm Dia Unmounted (FNS4-RND), 50x50x3mm Square Unmounted (coming soon)


Clear Focusing Filters

- Baader Clear Filter, 1"   (#FC-1)

- Baader Clear Filter, 2"   (#FC-2)

- Baader Clear Filter, 50.8mm Round (3mmThick)   (#FC-RND) 

- Baader Clear Filter, 50mm Square (3mm Thick)   (#FC-SQ) 


Comparison of Transmission curves and spectrums, taken using Baader Dados Spectrograph



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 NEW!! Baader f/2 Highspeed Narrowband CCD Filters

Baader's New f/2 Highspeed Narrowband Filters and Filtersets (1" and 2", H-alpha / O-III / S-II) are designed especially for the delicate requirements of extremely fast astrograph optics, such as Hyperstar, RASA, and ultra-fast instruments from TEC/AP/ASA/etc. Conventional narrowband filters cause a heavy loss in transmission due to the strong CWL-shift. In extreme cases the CWL even shifts out of the FWHM (CWL= Center-wavelength / FWHM= full width half maximum).

Therefore these filters have a CWL-preshift which matches f/2 to f/3 perfectly. Also the FWHM is optimized. In spite of the typical line broadening with such fast optical trains they are able to deliver maximum contrast. For the first time these filters allow the effective use of extremely fast optics for high contrast imaging of emission nebulae. Using these filters between f/1,8 and f/3,5 shows a dramatic improvement compared to any regular set of narrowband-filters.





Individual Filters

- Baader f/2 Highspeed-Filter H-Alpha, 1"   (#FHALHS-1)

- Baader f/2 Highspeed-Filter H-Alpha, 2"   (#FHALHS-2)

- Baader f/2 Highspeed-Filter O-III, 1"   (#FOIIIHS-1)

- Baader f/2 Highspeed-Filter O-III, 2"   (#FOIIIHS-2)

- Baader f/2 Highspeed-Filter S-II, 1"   (#FSIIHS-1)

- Baader f/2 Highspeed-Filter S-II, 2"   (#FSIIHS-2)


Filter Sets

- Set of 3 f/2 Highspeed-Filters (H-a/O-III/S-II): 1" (FHSS-1), 2" (FHSS-2),




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 NEW!! Baader 3.5nm Narrowband H-alpha Filters


Baader's New 3.5nm Narrowband Enforced H-alpha Filters  These three sizes of 3.5nm Enforced-Narrowband filters upen up the extremely narrow 3.5nm H-alpha world.  This enforced contrast provides more signal of the faintest nebula detail.  Manufacturing such ultra-narrow filters requires extreme coating homogeneity and very high Center Wavelenth Precision, which these filters have been designed for.  The intial production has centered on the most important sizes: 2"/50.8mm Round, and 50x50 Square - other sizes to follow.





- Baader 3.5nm Narrowband H-Alpha Filter, 2" Mounted (LPFC)  (FHALNE-2)

- Baader 3.5nm Narrowband H-Alpha Filter, 50.8mm Round (FHALNE-RD50)

- Baader 3.5nm Narrowband H-Alpha Filter, 50x50mm Square (FHALNE-SQ50)




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Baader LRGBC Filters



Simply put - Baader's new LRGBC anti-reflection filters deliver improved color separation and image quality without annoying halos. Unfortunately, their obvious improvements will likely cause many astro-imagers to re-take images of their favorite objects...

What makes the Baader filters so unique?  Through an extensive coating stack design and testing program, Baader has partnered with the world's leading thin film coating company to produce transmission curves that border on the ideal.  Their ultra steep cutoffs and high transmission (>95%) allowed Baader to do something to a degree no other RGB filter set can manage - they are able to effectively separate the important H-Beta and O-III lines.  The Baader Blue filter passes virtually all of the H-Beta and O-III lines, while the Green filter is able to capture all of the O-III line, without encroaching into the H-Beta line.  None of the light is wasted by either filter.  In this way, O-III is represented as it should be, a teal (blue-green) color, and H-Beta is captured solely in the blue. Never before has this degree of separation been achieved, and with such high transmission of both lines. 

In addition, the Green and Red filter passbands nearly touch, leaving only a sharp notch to block out the primary Mercury/Sodium light pollution line at 580nm.  The high transmission everywhere else delivers the shortest combined exposures possible with every detector.

In addition to their special transmission properties, the Baader coatings were developed from the outset with another key goal in mind - eliminate the annoying reflections present in other astro-filters.  To achieve this freedom from reflections required careful balancing of the coating stacks and further extensive testing.  The result can be seen in these two images, showing the freedom from reflections in the L and C Filters (click on the image for a larger version).  Image courtesy of Mr. Johannes Schedler.

The high optical quality of the Baader narrowband filters guarantees no loss in sharpness or contrast.  Each substrate is fine-optically polished plane parallel to deliver a smooth and accurate 1/4 wavefront over the entire surface.  Each filter is blocked and polished individually, not cut out of a larger plate of glass.  The special custom polishing operation sets Baader filters apart from the lower optical quality provided by standard commercially precision polished filter substrates used by most other filter manufacturers. 

Coatings are professionally applied in Germany by the most sophisticated equipment available today, ensuring high consistency for bandpass cutoffs, transmission, and out of band blocking.  The anti-reflection coatings are evenly balanced on both sides of the filters to reduce surface stresses and prevent deformation of the substrates. The ultra-hard ionbeam deposition ensures the coatings will never degrade from use or normal cleaning.   Unlike many competitive filters, Baader coats each filter individually.  Baader filters remain sealed at their coating edges for a long life without degradation (you can see evidence of this process by inspecting for a thin un-coated region at the very edge of the filter).  Though more costly, this process avoids the coating failures that can result when filters are simply 'biscuit cut' from bulk coated sheet glass, leaving ragged coating edges for moisture to penetrate and cause coatings to peel away from the glass.  Baader filters are intended for a lifetime of real-world use.


For more information on the unique performance and features of these filters,

please click the following link:

Baader LRGBC Anti-Reflection Filter Data Sheet (182 kB)



Noted astro-imager, Johannes Schedler (Panther Observatory), found the Baader filters to be superb at capturing colors as well as freedom from reflections.


"I am more than satisfied with the performance of the new Baader filter set. The absence of any reflections from bright stars makes clean-up procedures obsolete for many objects displaying foreground stars. The simple 1:1:1 RGB weighting together with a distinct color separation supplies deep star colors and fine details in galaxies and nebulas."

(Rosette image taken with TEC-140, 10 minutes per color, courtesy of Mr. Johannes Schedler, Panther Observatory).



Please click on the thumbnails below for some other  images taken by Mr. Schedler through the Baader LRGBC filters. 



NGC 3372 - Eta Carina

NGC 5128 - Centaurus A

M20 - Trifid Nebula



Baader LRGB filter sets and C-filters are available in four sizes, standard mounted 1", 2", as well as 50.8mm diameter round and 50mm Square bare substrates (unmounted) for use in larger format cameras.   Clear filters for focusing and full-throughput are also available.


NOTE for Users of the Unmounted Filters (RND and SQ):  The preferred oriention of the filter is to have the highest reflectivity side facing skyward. 







Red Spectrogram

(transmission of solar spectrum)

Green Spectrogram

(transmission of solar spectrum)

Blue Spectrogram

(transmission of solar spectrum)

RGB Combined Spectrogram

(transmission of solar spectrum)


Filter Sets (set of 4 filters, filters not sold individually)

- Baader LRGB Filter Set, 1.25"   (#FLRGB-1)

- Baader LRGB Filter Set, 2"   (#FLRGB-2)

- Baader LRGB Filter Set, 50.8mm Round (3mmThick)  (#FLRGB-RND)

- Baader LRGB Filter Set, 50mm Square (3mm Thick)   (#FLRGB-SQ)


Clear Focusing Filters

- Baader Clear Filter, 1.25"   (#FC-1)

- Baader Clear Filter, 2"   (#FC-2)

- Baader Clear Filter, 50.8mm Round (3mmThick)   (#FC-RND) 

- Baader Clear Filter, 50mm Square (3mm Thick)   (#FC-SQ) 




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2" Filter Holder for DSLRs


Adapt Baader's 2" Astro Filters onto practically any DSLR camera lens for widefield astrophotography.  Uses Hyperion DT Rings from 28mm to 82mm for coupling onto the camera lenses front filter threads.  Great for UV imagers, too (flower and forensic imaging)


# DSLR-2  2" Filter Front Holder (M48/M54)

(Has internal M48 filter threads on one side for attaching 2" Astro-Filters, external M54 threads on other side for attachment of Baader Hyperino DT-Rings)





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Last Update 01/05/15


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