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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

$1,186.46 - $1,186.46
$1,186.46
$1,186.46 - $1,186.46
$1,186.46

Askar 3nm Colour Magic Ha/OIII & SII/OIII (E1+E2) Filter Package

ASK-CM-E1E2
1 en stock

Enables SHO "Hubble Palette" imaging with a one-shot-color (OSC) camera Includes two 3nm dual-bandpass filters: E1 (Hα+OIII) and E2 (SII+OIII) Iso...

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$1,186.46 - $1,186.46
$1,186.46
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$1,186.46
$605.00 - $605.00
$605.00
$605.00 - $605.00
$605.00

Askar 3nm Colour Magic Ultra Ha/OIII E1 Filter - 2"

ASK-ASKAR2DBE1
1 en stock

Dual-bandpass for Hydrogen-alpha (656.6nm) and Oxygen-III (500.7nm) Ultra-narrow 3.7nm (Ha) and 4.0nm (OIII) FWHM bandwidths 85% peak transmittanc...

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$605.00 - $605.00
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$598.89 - $598.89
$598.89
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$598.89

Askar 3nm Colour Magic Ultra OIII/SII E2 Filter - 2"

ASK-ASKAR2DBE2
1 en stock

Dual-bandpass design captures OIII (500.7nm) and SII (672nm) simultaneously Narrow 3.7nm (OIII) and 4.0nm (SII) FWHM for high-contrast imaging Pea...

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$598.89 - $598.89
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$625.00 - $625.00
$625.00
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$625.00

Ensemble de filtres Askar 6 nm Colour Magic Ha/OIII et SII/OIII (D1+D2)

ASK-CM-D1D2
1 en stock

Ensemble double filtre : 6 nm Ha/OIII (D1) et 6 nm SII/OIII (D2) Optimisé pour l'astrophotographie à contraste élevé et à bande étroite ...

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$319.00 - $319.00
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Filtre Askar Color Magic Super Ha/OIII D1 6 nm - 2"

ASK-ASK2DNHOD1
1 en stock

Filtre à double bande étroite de 6 nm de largeur de bande pour les longueurs d'onde Ha et OIII Taille de 2 pouces pour une compatibilité avec d...

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$319.00 - $319.00
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Filtre Askar Color Magic Super SII/OIII D2 6 nm - 2"

ASK-ASK2DNSOD2
1 en stock

Filtre à double bande étroite de 6 nm pour les longueurs d'onde SII et OIII Taille de 2 pouces pour la compatibilité avec diverses config...

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$319.00 - $319.00
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$225.00 - $225.00
$225.00
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$225.00

Ensemble de filtres Askar Colour Magic Ha/OIII et SII/OIII (C1+C2)

ASK-CM-C1C2
2 en stock

Pack double filtre pour l'astrophotographie : Ha/OIII (C1) et SII/OIII (C2) Optimisé pour capturer de superbes images de nébuleuse avec u...

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$225.00 - $225.00
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$119.00 - $119.00
$119.00
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$119.00

Filtre Askar Color Magic Ha/OIII C1 - 2"

ASK-ASKAR2DBC1
2 en stock

Filtre duo-bande Ha+OIII Améliore la qualité de l'image Transmission élevée supérieure à 90 % à sa longueur d'onde centrale ...

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$119.00

Filtre Askar Color Magic SII/OIII C2 - 2"

ASK-ASKAR2DBC2
3 en stock

Filtre duo-bande SII+OIII Améliore la qualité de l'image Transmission élevée supérieure à 90 % à sa longueur d'onde centrale ...

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$119.00 - $119.00
$119.00
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Askar Multifunctional Filter Drawer
$164.00 - $164.00
$164.00
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$164.00

Askar Multifunctional Filter Drawer

ASK-ASKAR54FD
2 en stock

Integrates telescope and camera adapters to reduce complexity Accepts five common filter formats in a single system Supports 1.25" and 2" mounted ...

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$164.00 - $164.00
$164.00
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Économisez 25% Économisez %
$484.00
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Astrodon Filtre H-alpha - 5nm

DON-HA5_31R
1 restant!

H-α (hydrogène-alpha) à 656 nm (nanomètres) est de couleur rouge foncé et le filtre à bande étroite le plus populaire. L'hydrogène est omniprésent...

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$484.00
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$363.00
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Économisez 25% Économisez %
Épuisé
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Astrodon Filtre SII - 5nm

DON-SII5_31R

Si vous voulez l'apparence des images du télescope spatial Hubble (HST), comme les célèbres "Piliers de la Création" (la nébuleuse de l'Aigle, Mes...

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$484.00
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Épuisé
$946.00 - $2,105.00
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Ensemble de filtres ultra-rapides Baader 3,5/4 nm f/2 - H-alpha/O-III/S-II optimisés CMOS

Options available

f/2 Highspeed Filterset composé de 3 filtres : H-alpha, O III et S II. Les filtres à bande étroite à grande vitesse sont spécialement conçus pour...

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$946.00 - $2,105.00
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$929.00 - $1,982.00
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Ensemble de filtres à bande étroite Baader 3,5 nm / 4 nm - H-alpha/O-III/S-II optimisé CMOS

Options available
1 variants in stock

Ensemble de filtres Baader H-alpha / O-III / S-II Ultra-Narrowband (bande étroite) - Premium Grade 3,5/4 nm demi-largeur (pour harmoniser le te...

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$929.00 - $1,982.00
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$320.00 - $692.00
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$320.00

Filtre Baader 4nm Ultra-Narrowband OIII - Optimisé CMOS

Options available
1 variants in stock

Ensemble de filtres Baader H-alpha / O-III / S-II Ultra-Narrowband (bande étroite) - Premium Grade 3,5/4 nm demi-largeur (pour harmoniser le tem...

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$320.00 - $692.00
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$548.00 - $1,310.00
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$548.00

Ensemble de filtres haute vitesse Baader 6,5 nm f/2 - H-alpha/O-III/S-II optimisé CMOS

Options available
1 variants in stock

f/2 Highspeed Filterset composé de 3 filtres : H-alpha, O III et S II. Les filtres à bande étroite à grande vitesse sont spécialement conçus pour...

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$548.00 - $1,310.00
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$188.00 - $481.00
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$188.00

Filtre Baader 6.5nm H-alpha - Optimisé CMOS

Options available

Ensemble de filtres à bande étroite Baader H-alpha / O-III / S-II - Qualité de précision 6,5 nm FWHM, recommandé pour les systèmes optiques de ...

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$188.00 - $481.00
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$188.00
$512.00 - $1,287.00
$512.00 - $1,287.00
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$512.00

Ensemble de filtres à bande étroite Baader 6,5 nm - H-alpha/O-III/S-II optimisés CMOS

Options available

Ensemble de filtres à bande étroite Baader H-alpha / O-III / S-II - Qualité de précision 6,5 nm FWHM, recommandé pour les systèmes optiques de f...

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$512.00 - $1,287.00
$512.00 - $1,287.00
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$512.00
$179.00 - $470.00
$179.00 - $470.00
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$179.00

Filtre Baader 6.5nm OIII - Optimisé CMOS

Options available

6,5 nm FWHM, recommandé pour les systèmes optiques de f/10 à f/3,5 Reflex-Blocker ™ à revêtement dur et planoptiquement poli - avec bords de ...

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$179.00 - $470.00
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$176.00 - $468.00
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$176.00

Filtre Baader 6.5nm SII - Optimisé CMOS

Options available

6,5 nm FWHM, recommandé pour les systèmes optiques de f/10 à f/3,5 Reflex-Blocker ™ à revêtement dur et planoptiquement poli - avec bords de ...

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$176.00 - $468.00
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$176.00
$111.00 - $111.00
$111.00
$111.00 - $111.00
$111.00

Baader Filtre de Conversion Astro ACF - pour Canon EOS 300

BAA-2459211

Filtre de conversion DSLR pour Canon EOS 300D Transformez votre reflex numérique Canon en une superbe caméra Astro pour le ciel profond. Les filtr...

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$111.00 - $111.00
$111.00
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$111.00
$128.00 - $128.00
$128.00
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$128.00

Baader Filtre de Conversion Astro ACF - pour Canon EOS 350D/10D/20D/30D

BAA-2459212

Filtre de conversion DSLR pour Canon EOS 350D/20D/10D/30D. Stock limité Transformez votre reflex numérique Canon en une superbe caméra Astro pour l...

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$128.00 - $128.00
$128.00
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$128.00
$108.00 - $108.00
$108.00
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$108.00

Baader Filtre de Conversion Astro BCF - for Canon EOS

BAA-2459213
1 en stock

Filtre de conversion DSLR pour appareils photo Canon APS-C (tous les derniers modèles, ainsi que les anciens EOS 7D/40D/50D/60D/400D/450D/500D/550D...

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$108.00 - $108.00
$108.00
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$108.00
$93.00 - $188.00
$93.00 - $188.00
$93.00 - $188.00
$93.00

Baader C2 Swan-Band Comet Filter (15nm)

Options available
2 variants in stock

Targets C2 Swan Bands in comet gas tails 15nm bandpass for high-contrast views O-III parallel transmission for nebula observation Available in 1.2...

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$93.00 - $188.00
$93.00 - $188.00
$93.00 - $188.00
$93.00

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.