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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.

Filtres

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.

Filtres

$255.00 - $490.00
$255.00 - $490.00
$255.00 - $490.00
$255.00

Antlia Filtre à bande étroite H-alpha Pro de 3nm

Options available
9 variants in stock

Longueur d'onde centrale H-alpha de 656,3 nm Petit FHWM de 3 nm Transmission de crête élevée > 88 % Halos minimisés sur les étoiles b...

Afficher tous les détails
$255.00 - $490.00
$255.00 - $490.00
$255.00 - $490.00
$255.00
$268.00 - $515.00
$268.00 - $515.00
$268.00 - $515.00
$268.00

Antlia 3nm Narrowband H-alpha Pro Highspeed Filter - f/2.6 to f/3.6

Options available
1 variants in stock

Pre-shifted 656.3nm H-alpha Central Wavelength for High-Speed Systems Optimized 3nm FHWM for f/2.6–f/3.6 High >90% Peak Transmission Enhanced S...

Afficher tous les détails
$268.00 - $515.00
$268.00 - $515.00
$268.00 - $515.00
$268.00
$255.00 - $490.00
$255.00 - $490.00
$255.00 - $490.00
$255.00

Antlia Filtre à bande étroite OIII Pro de 3nm

Options available
9 variants in stock

Le filtre à bande étroite Antlia OIII Pro optimise le FWHM (pleine largeur moitié maximum) à 3 nm passe-bande . Au fur et à mesure que la bande pa...

Afficher tous les détails
$255.00 - $490.00
$255.00 - $490.00
$255.00 - $490.00
$255.00
$268.00 - $515.00
$268.00 - $515.00
$268.00 - $515.00
$268.00

Antlia 3nm Narrowband OIII Pro Highspeed Filter - f/2.6 to f/3.6

Options available
1 variants in stock

Pre-shifted 500.7nm OIII Central Wavelength for High-Speed Systems Optimized 3nm FHWM for f/2.6–f/3.6 High >90% Peak Transmission Enhan...

Afficher tous les détails
$268.00 - $515.00
$268.00 - $515.00
$268.00 - $515.00
$268.00
$255.00 - $490.00
$255.00 - $490.00
$255.00 - $490.00
$255.00

Antlia Filtre à bande étroite SII Pro de 3nm

Options available
7 variants in stock

Le filtre à bande étroite Antlia SII Pro optimise le FWHM (pleine largeur moitié maximum) à une bande passante de 3 nm. Au fur et à mesure que la ...

Afficher tous les détails
$255.00 - $490.00
$255.00 - $490.00
$255.00 - $490.00
$255.00
$271.64 - $522.28
$271.64 - $522.28
$271.64 - $522.28
$271.64

Antlia 3nm Narrowband SII Pro Highspeed Filter - f/2.6 to f/3.6

Options available
1 variants in stock

Pre-shifted 500.7nm OIII Central Wavelength for High-Speed Systems Optimized 3nm FHWM for f/2.6–f/3.6 High >90% Peak Transmission Enhan...

Afficher tous les détails
$271.64 - $522.28
$271.64 - $522.28
$271.64 - $522.28
$271.64
$185.00 - $350.00
$185.00 - $350.00
$185.00 - $350.00
$185.00

Antlia Filtre à bande étroite H-alpha Edge de 4.5nm

Options available
8 variants in stock

Le filtre à bande étroite Antlia H-alpha EDGE optimise le FWHM (pleine largeur demi-maximum) à une bande passante de 4,5 nm. La suppression de la...

Afficher tous les détails
$185.00 - $350.00
$185.00 - $350.00
$185.00 - $350.00
$185.00
$185.00 - $350.00
$185.00 - $350.00
$185.00 - $350.00
$185.00

Antlia Filtre à bande étroite OIII Edge de 4.5nm

Options available
8 variants in stock

Le filtre à bande étroite Antlia OIII EDGE optimise le FWHM (pleine largeur demi-maximum) à une bande passante de 4,5 nm. La suppression de la de...

Afficher tous les détails
$185.00 - $350.00
$185.00 - $350.00
$185.00 - $350.00
$185.00
$185.00 - $350.00
$185.00 - $350.00
$185.00 - $350.00
$185.00

Antlia Filtre à bande étroite SII Edge de 4.5nm

Options available
7 variants in stock

Le filtre à bande étroite Antlia SII EDGE optimise le FWHM (pleine largeur demi-maximum) à une bande passante de 4,5 nm. La suppression de la den...

Afficher tous les détails
$185.00 - $350.00
$185.00 - $350.00
$185.00 - $350.00
$185.00
$390.00 - $390.00
$390.00
$390.00 - $390.00
$390.00

Antlia ALP-T Dual Band Ha&OIII 3nm

ANT-ALP-T-3NM-HAOIII
5 en stock

Precise Narrowband Filtering for Exceptional Contrast Enhanced Transmission for Superior Signal-to-Noise Ratio ...

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$390.00 - $390.00
$390.00
$390.00 - $390.00
$390.00
$710.00 - $710.00
$710.00
$710.00 - $710.00
$710.00

Antlia ALP-T Dual Band Ha&OIII 3nm + SII&Hb 3.5nm 2" Filter Set

ANT-ALP-T-3NM-KIT

Precise Narrowband Filtering for Exceptional Contrast Enhanced Transmission for Superior Signal-to-Noise Ratio ...

Afficher tous les détails
$710.00 - $710.00
$710.00
$710.00 - $710.00
$710.00
$360.00 - $360.00
$360.00
$360.00 - $360.00
$360.00

Antlia ALP-T Dual Band SII&Hβ 3.5nm

ANT-ALP-T-3NM-SIIHB
2 en stock

Precise Narrowband Filtering for Exceptional Contrast Enhanced Transmission for Superior Signal-to-Noise Ratio Anti-Reflection Coating to Reduce H...

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$360.00 - $360.00
$360.00
$360.00 - $360.00
$360.00
$690.00 - $690.00
$690.00
$690.00 - $690.00
$690.00

Antlia Kit de filtres duoband ALP-T 5nm Ha/OIII et SII/Hb - 2"

ANT-ALP-T-SET

$690.00 - $690.00
$690.00
$690.00 - $690.00
$690.00
$380.00 - $380.00
$380.00
$380.00 - $380.00
$380.00

Antlia Filtre duoband ALP-T Ha/OIII de 5nm

ANT-ALP-T-2

L' Antlia ALP-T double bande 5 nm Le filtre Ha&OIII est un filtre passe-ligne double conçu pour être utilisé principalement avec les appareil...

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$380.00 - $380.00
$380.00
$380.00 - $380.00
$380.00
$380.00 - $380.00
$380.00
$380.00 - $380.00
$380.00

Antlia Filtre duoband ALP-T haute vitesse Ha/OIII de 5nm

ANT-ALP-T-HS-2

Les filtres haute vitesse ALP-T double bande 5 nm sont encore optimisés pour fonctionner avec des systèmes d'imagerie à haute vitesse en décalant...

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$380.00 - $380.00
$380.00
$380.00 - $380.00
$380.00
$350.00 - $350.00
$350.00
$350.00 - $350.00
$350.00

Antlia Filtre duoband ALP-T SII/Hb de 5nm

ANT-ALP-T-SII-HB-2

Le filtre SII&Hb double bande 5 nm ALP-T est un filtre passe-ligne double, qui laisse passer la ligne rouge foncé Sulphur-II et la ligne bleu...

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$350.00 - $350.00
$350.00
$350.00 - $350.00
$350.00
$169.00 - $169.00
$169.00
$169.00 - $169.00
$169.00

Antlia CH4 Methane Filter - 1.25"

ANT-CH4
1 en stock

Antlia methane (CH4) filter is a specialized filter that allows light in the near infrared portion of the spectrum centered at 889nm to pass throug...

Afficher tous les détails
$169.00 - $169.00
$169.00
$169.00 - $169.00
$169.00
$99.00 - $99.00
$99.00
$99.00 - $99.00
$99.00

Antlia Filtre visuel H-beta et OIII - 1.25"

ANT-HB-OIII-1.25
3 en stock

Le filtre Antlia HB-OIII est conçu spécifiquement pour l'observation visuelle nocturne des nébuleuses à contraste élevé et l'astrophotographie du...

Afficher tous les détails
$99.00 - $99.00
$99.00
$99.00 - $99.00
$99.00
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Antlia Filtre IR-Pass 685nm - 1.25"

ANT-IR685
3 en stock

Le filtre Antlia IR Pass 685 nm est un filtre absorbant qui laisse passer la lumière infrarouge avec des longueurs d'onde supérieures à 685 nm. À...

Afficher tous les détails
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00

Antlia Filtre IR-Pass 850nm - 1.25"

ANT-IR850
3 en stock

Le filtre Antlia IR Pass 850 nm est un filtre absorbant qui laisse passer la lumière infrarouge avec des longueurs d'onde supérieures à 850 nm. I...

Afficher tous les détails
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
$300.00 - $600.00
$300.00 - $600.00
$300.00 - $600.00
$300.00

Antlia Kit de filtres LRGB-V Pro

Options available
9 variants in stock

Les filtres de la série Antlia LRGB-V Pro sont conçus pour les caméras monochromes qui utilisent à la fois des capteurs CCD et CMOS. Les capteurs ...

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$300.00 - $600.00
$300.00 - $600.00
$300.00 - $600.00
$300.00
$198.00 - $198.00
$198.00
$198.00 - $198.00
$198.00

Antlia Filtre Quad Band anti-pollution lumineuse - 2"

ANT-QUAD-2
5 en stock

Le filtre anti-pollution lumineuse Antlia Quad Band est un filtre de suppression de lumière pour les caméras couleur et monochromes. Il est capabl...

Afficher tous les détails
$198.00 - $198.00
$198.00
$198.00 - $198.00
$198.00
$179.00 - $179.00
$179.00
$179.00 - $179.00
$179.00

Antlia Filtre Triband RGB Ultra

ANT-TRIBAND-V2
4 en stock

Il est conçu pour la suppression de la pollution lumineuse pour les caméras OSC et Mono. La conception spectrale a sélectionné les informations le...

Afficher tous les détails
$179.00 - $179.00
$179.00
$179.00 - $179.00
$179.00
$199.00 - $199.00
$199.00
$199.00 - $199.00
$199.00

Antlia Filtre U-Venus - 1.25"

ANT-UVENUS
2 en stock

Le filtre Antlia Venus-U est conçu pour imager la structure nuageuse de Vénus et Jupiter avec des caméras CCD sur un télescope. Les détails des n...

Afficher tous les détails
$199.00 - $199.00
$199.00
$199.00 - $199.00
$199.00

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.