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Filters

A filter decides what light reaches your sensor or your eye, and under Canadian suburban skies that decision often matters more than aperture. The right narrowband filter can make a nebula imageable from a driveway that visually shows almost nothing. David Astro carries filters in Canada — narrowband, LRGB, light pollution, planetary, solar and scientific — in 1.25", 2", 31 mm, 36 mm and unmounted formats, shipped from Canadian stock.

Filter selection is where our team spends a lot of time, because bandwidth, f-ratio and sensor size interact in ways that are not obvious from a product page. Tell us your telescope and camera and we will recommend a set that works together.

Filters

CA$401.00 - CA$605.00
CA$401.00 - CA$605.00
CA$401.00 - CA$605.00
CA$401.00

Baader Color Filter Set - 6 Colors

Options available

Set of 6 essential color filters for lunar and planetary observing Planeoptically polished to maintain image sharpness at high magnification Doubl...

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CA$401.00 - CA$605.00
CA$401.00 - CA$605.00
CA$401.00 - CA$605.00
CA$401.00
CA$130.00 - CA$209.00
CA$130.00 - CA$209.00
CA$130.00 - CA$209.00
CA$130.00

Baader Contrast-Booster Filter

Options available
2 variants in stock

Enhances contrast for lunar and planetary observing Significantly darkens skyglow background Reveals subtle details in Jupiter's cloud belts and M...

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CA$130.00 - CA$209.00
CA$130.00 - CA$209.00
CA$130.00 - CA$209.00
CA$130.00
CA$134.00 - CA$194.00
CA$134.00 - CA$194.00
CA$134.00 - CA$194.00
CA$134.00

Baader Fringe-Killer Filter

Options available
2 variants in stock

Reduces violet/blue color fringing in achromatic refractors Blocks unfocused near-infrared (NIR) light for sharper digital images Maintains a natu...

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CA$134.00 - CA$194.00
CA$134.00 - CA$194.00
CA$134.00 - CA$194.00
CA$134.00
CA$153.00 - CA$370.00
CA$153.00 - CA$370.00
CA$153.00 - CA$370.00
CA$153.00

Baader H-Alpha CCD Filter -35nm

Options available

Premium grade H-alpha interline chip CCD-filter for fast optical systems f/10 to f/2.8 IR-blocked NO halos, NO reflections, NO ghosting Non-aging ...

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CA$153.00 - CA$370.00
CA$153.00 - CA$370.00
CA$153.00 - CA$370.00
CA$153.00
CA$75.00 - CA$110.00
CA$75.00 - CA$110.00
CA$75.00 - CA$110.00
CA$75.00

Baader Individual Color Filter - Dark Blue, Bright Blue, Green, Yellow, Red, Orange

Options available

Available in 6 distinct colors for targeted planetary observation Planeoptically polished to 30 arcseconds for zero image degradation 7-layer anti...

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CA$75.00 - CA$110.00
CA$75.00 - CA$110.00
CA$75.00 - CA$110.00
CA$75.00
CA$132.00 - CA$209.00
CA$132.00 - CA$209.00
CA$132.00 - CA$209.00
CA$132.00

Baader IR-Pass Filter 685nm

Options available
1 variants in stock

685nm Infrared (IR) Pass Filter Transmits deep-red light starting from 670nm Dramatically reduces the image-blurring effects of atmospheric seeing...

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CA$132.00 - CA$209.00
CA$132.00 - CA$209.00
CA$132.00 - CA$209.00
CA$132.00
CA$436.00 - CA$1,216.00
CA$436.00 - CA$1,216.00
CA$436.00 - CA$1,216.00
CA$436.00

Baader LRGB Filter Set - CMOS-Optimized

Options available

Designed specifically to eliminate reflections and halos with modern CMOS sensors Balanced RGB transmission enables simplified 1:1:1 exposure rati...

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CA$436.00 - CA$1,216.00
CA$436.00 - CA$1,216.00
CA$436.00 - CA$1,216.00
CA$436.00
CA$348.00 - CA$348.00
CA$348.00
CA$348.00 - CA$348.00
CA$348.00

Baader Methane Filter 889nm - 8nm 1.25"

BAA-2458295

889nm Center Wavelength 8nm Bandwidth (FWHM) Targets Methane Absorption Band High-Contrast Planetary Imaging 1.25" Filter Format Description FA...

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CA$348.00 - CA$348.00
CA$348.00
CA$348.00 - CA$348.00
CA$348.00
CA$130.00 - CA$213.00
CA$130.00 - CA$213.00
CA$130.00 - CA$213.00
CA$130.00

Baader Moon & Skyglow Filter

Options available

Enhances lunar and planetary contrast with a Neodymium glass substrate Suppresses skyglow from artificial lighting without aggressive color shifti...

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CA$130.00 - CA$213.00
CA$130.00 - CA$213.00
CA$130.00 - CA$213.00
CA$130.00
CA$70.00 - CA$118.00
CA$70.00 - CA$118.00
CA$70.00 - CA$118.00
CA$70.00

Baader Neutral Density Filter - ND 0.6/0.9/1.8/3.0

Options available
6 variants in stock

Four Neutral Density Options: ND 0.6, ND 0.9, ND 1.8, and ND 3.0 Two Standard Sizes: 1.25" and 2" round mounted cells Coatings: Baader Planetarium...

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CA$70.00 - CA$118.00
CA$70.00 - CA$118.00
CA$70.00 - CA$118.00
CA$70.00
CA$216.00 - CA$1,005.00
CA$216.00 - CA$1,005.00
CA$216.00 - CA$1,005.00
CA$216.00

Baader Photometric SLOAN/SDSS g' Individual Filter

Options available

SLOAN/SDSS g' Bandpass: Conforms to the modern standard for astronomical photometry. Photometric Grade: Produces scientifically valid data for r...

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CA$216.00 - CA$1,005.00
CA$216.00 - CA$1,005.00
CA$216.00 - CA$1,005.00
CA$216.00
CA$212.00 - CA$1,011.00
CA$212.00 - CA$1,011.00
CA$212.00 - CA$1,011.00
CA$212.00

Baader Photometric SLOAN/SDSS i' Individual Filter

Options available

SLOAN/SDSS i' Standard: Conforms to the standardized Sloan Digital Sky Survey photometric system for consistent, comparable scientific data. Pho...

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CA$212.00 - CA$1,011.00
CA$212.00 - CA$1,011.00
CA$212.00 - CA$1,011.00
CA$212.00
CA$217.00 - CA$1,008.00
CA$217.00 - CA$1,008.00
CA$217.00 - CA$1,008.00
CA$217.00

Baader Photometric SLOAN/SDSS r' Individual Filter

Options available

Conforms to the scientific SLOAN/SDSS r' photometric system Engineered for professional and amateur astronomical research Available in 8 formats, ...

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CA$217.00 - CA$1,008.00
CA$217.00 - CA$1,008.00
CA$217.00 - CA$1,008.00
CA$217.00
CA$225.00 - CA$1,012.00
CA$225.00 - CA$1,012.00
CA$225.00 - CA$1,012.00
CA$225.00

Baader Photometric SLOAN/SDSS u' Individual Filter

Options available

Standardized SLOAN/SDSS u'-band photometric filter Isolates the near-ultraviolet (UV) spectrum for scientific analysis Designed for repeatable, hi...

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CA$225.00 - CA$1,012.00
CA$225.00 - CA$1,012.00
CA$225.00 - CA$1,012.00
CA$225.00
CA$1,158.00 - CA$5,751.00
CA$1,158.00 - CA$5,751.00
CA$1,158.00 - CA$5,751.00
CA$1,158.00

Baader Photometric SLOAN/SDSS ugriz' Filter Set

Options available

Conforms to the Sloan Digital Sky Survey (SDSS) photometric system Includes five filters: u' (ultraviolet), g' (green), r' (red), i' (infrared), a...

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CA$1,158.00 - CA$5,751.00
CA$1,158.00 - CA$5,751.00
CA$1,158.00 - CA$5,751.00
CA$1,158.00
CA$206.00 - CA$1,017.00
CA$206.00 - CA$1,017.00
CA$206.00 - CA$1,017.00
CA$206.00

Baader Photometric SLOAN/SDSS y' Individual Filter

Options available

Conforms to the SLOAN/SDSS y' photometric standard Designed for scientific magnitude measurements Ideal for variable star and exoplanet transit re...

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CA$206.00 - CA$1,017.00
CA$206.00 - CA$1,017.00
CA$206.00 - CA$1,017.00
CA$206.00
CA$204.00 - CA$1,014.00
CA$204.00 - CA$1,014.00
CA$204.00 - CA$1,014.00
CA$204.00

Baader Photometric SLOAN/SDSS z-s' Individual Filter

Options available

Photometric filter for the SLOAN/SDSS z-s' bandpass Conforms to the Sloan Digital Sky Survey photometric system standard Enables calibrated, scien...

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CA$204.00 - CA$1,014.00
CA$204.00 - CA$1,014.00
CA$204.00 - CA$1,014.00
CA$204.00
CA$1,018.00 - CA$4,776.00
CA$1,018.00 - CA$4,776.00
CA$1,018.00 - CA$4,776.00
CA$1,018.00

Baader Photometric UBVRI Filter Set

Options available

Standardized UBVRI Bessel passbands for scientific photometry Enables measurement of variable stars, asteroids, and exoplanet transits Precision p...

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CA$1,018.00 - CA$4,776.00
CA$1,018.00 - CA$4,776.00
CA$1,018.00 - CA$4,776.00
CA$1,018.00
CA$204.00 - CA$982.00
CA$204.00 - CA$982.00
CA$204.00 - CA$982.00
CA$204.00

Baader Photometric UBVRI-B Individual Filter

Options available

Conforms to the standardized Johnson-Cousins/Bessel B-band passband Designed for research-grade scientific photometry Advanced anti-reflection and...

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CA$204.00 - CA$982.00
CA$204.00 - CA$982.00
CA$204.00 - CA$982.00
CA$204.00
CA$231.00 - CA$1,041.00
CA$231.00 - CA$1,041.00
CA$231.00 - CA$1,041.00
CA$231.00

Baader Photometric UBVRI-I Individual Filter

Options available

Conforms to the Johnson-Cousins UBVRI Photometric System Optimized for the Bessel I-Band (Infrared) Homofocal Design for Parfocal Operation with o...

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CA$231.00 - CA$1,041.00
CA$231.00 - CA$1,041.00
CA$231.00 - CA$1,041.00
CA$231.00
CA$203.00 - CA$983.00
CA$203.00 - CA$983.00
CA$203.00 - CA$983.00
CA$203.00

Baader Photometric UBVRI-R Individual Filter

Options available

Conforms to the Johnson-Cousins-Bessel R-Band Photometric Standard Engineered for Scientific Photometry and Data Collection Plane-Parallel Substra...

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CA$203.00 - CA$983.00
CA$203.00 - CA$983.00
CA$203.00 - CA$983.00
CA$203.00
CA$231.00 - CA$1,056.00
CA$231.00 - CA$1,056.00
CA$231.00 - CA$1,056.00
CA$231.00

Baader Photometric UBVRI-U Individual Filter

Options available
1 variants in stock

Conforms to the Johnson-Cousins/Bessel U-Band Photometric Standard Designed for Scientific Photometry of Variable Stars and Stellar Classification...

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CA$231.00 - CA$1,056.00
CA$231.00 - CA$1,056.00
CA$231.00 - CA$1,056.00
CA$231.00
CA$206.00 - CA$979.00
CA$206.00 - CA$979.00
CA$206.00 - CA$979.00
CA$206.00

Baader Photometric UBVRI-V Individual Filter

Options available
1 variants in stock

Bessel V-Band Standard: Precisely conforms to the internationally recognized Johnson-Cousins-Bessel V-band for consistent, scientific-grade magni...

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CA$206.00 - CA$979.00
CA$206.00 - CA$979.00
CA$206.00 - CA$979.00
CA$206.00
Baader Planetarium Baader 3.5 / 4nm f/3 Ultra-Highspeed Filter-Set 1.25" – CMOS-optimized (H-alpha / O-III / S-II)
CA$1,130.00 - CA$2,457.00
CA$1,130.00 - CA$2,457.00
CA$1,130.00 - CA$2,457.00
CA$1,130.00

Baader Planetarium 3.5 / 4nm f/3 Ultra-Highspeed Filter-Set – CMOS-optimized (H-alpha / O-III / S-II)

Options available

3.5 / 4nm Ultra-Narrow H-alpha, O-III & S-II Bandpasses Pre-Shifted for Fast f/3 "Ultra-Highspeed" Optical Systems CMOS-Optimized with Anti-Re...

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CA$1,130.00 - CA$2,457.00
CA$1,130.00 - CA$2,457.00
CA$1,130.00 - CA$2,457.00
CA$1,130.00

Filter Types and When Each One Earns Its Place

Filters do not add signal. They remove unwanted light so that the signal you want has better contrast against the background. Choosing well means knowing which unwanted light you are fighting.

  • Narrowband filters: Ha, OIII and SII passbands, typically 3 to 12 nm. Narrower bands reject more light pollution and moonlight but demand accurate focus and longer exposures.
  • LRGB filter sets: Parfocal luminance, red, green and blue for colour imaging with monochrome sensors, with the luminance channel carrying most of the detail.
  • Light pollution filters: Broadband rejection of mercury and sodium emission lines. Effective against older street lighting and much less effective against broad-spectrum LED.
  • Planetary and colour filters: Wratten-standard colour filters that raise contrast on specific planetary features — a red or orange filter on Mars, blue on Jupiter's belts.
  • Solar filters: Full-aperture white-light filters for safe observation of sunspots and transits.
  • Neutral density and polarizing: Variable brightness reduction for lunar observing without altering colour balance.

Why Choose David Astro for Filters

A filter that performs beautifully at f/7 can produce a shifted passband and soft results at f/3. That is the kind of detail worth asking about before ordering.

  • F-ratio matched recommendations: Narrowband passbands shift blueward in fast optical systems, so we recommend filters specified for your focal ratio rather than the narrowest available.
  • Sensor size and vignetting: We size filters to your sensor diagonal and filter wheel placement, so an undersized filter does not clip your corners.
  • Spacing accounted for: Filter glass shifts focus by roughly a third of its thickness, and we include that in the back-focus calculation we provide.
  • Authorized dealer: Genuine filters with full manufacturer warranty and verified coatings, in Canadian inventory and shipped domestically.
  • Ships from Canada: No duties or brokerage charges for Canadian buyers.

Filters in Canada — Frequently Asked Questions

Do light pollution filters still work under LED streetlights?
Much less well than they did under sodium lighting. LED emits across a broad spectrum, so there is no narrow band to reject. Narrowband filters remain effective because they pass only emission lines regardless of what the streetlight does.
How narrow should my Ha filter be?
For f/5 and slower, 3 to 5 nm gives excellent contrast. Below about f/4, the incident light cone shifts the passband and a 6 to 7 nm filter, or one specified for fast optics, performs better.
What size filters do I need?
Match the sensor diagonal plus the distance from filter to sensor. A 36 mm filter typically covers APS-C in a standard wheel; full frame usually needs 50 mm square or unmounted 2 inch.
Are filters shipped from Canada?
Yes, in-stock filters are held in our Canadian warehouse and reach Canadian customers without customs handling.

Building a filter set?

Tell us your telescope, camera and sky conditions and we will recommend the right bandwidths and sizes. Canadian stock, fast domestic shipping.