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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

SVBONY SV227 SHO 5nm H-Alpha OIII SII Narrowband Filter Set - 1.25"
SVBONY SV227 SHO 5nm H-Alpha OIII SII Narrowband Filter Set - 1.25"
CA$235.00 - CA$235.00
CA$235.00
CA$235.00 - CA$235.00
CA$235.00

SVBONY SV227 SHO 5nm H-Alpha OIII SII Narrowband Filter Set - 1.25"

SV-W9187A

Complete 1.25-inch SHO (SII, H-Alpha, OIII) filter set Tight 5nm bandpass for high-contrast imaging Peak transmission rate of ≥90% at key waveleng...

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CA$235.00 - CA$235.00
CA$235.00
CA$235.00 - CA$235.00
CA$235.00
SVBONY SV227 SII 5nm Narrowband Filter - 2"
SVBONY SV227 SII 5nm Narrowband Filter - 2"
CA$131.00 - CA$131.00
CA$131.00
CA$131.00 - CA$131.00
CA$131.00

SVBONY SV227 SII 5nm Narrowband Filter - 2"

SV-W9187DA

Captures Sulfur-II (SII) emission at a 672nm center wavelength Extremely narrow 5nm bandpass for maximum contrast Peak light transmission of ≥90% ...

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CA$131.00 - CA$131.00
CA$131.00
CA$131.00 - CA$131.00
CA$131.00
SVBONY SV231 Fringe Killer Color Correction Filter
CA$43.00 - CA$56.00
CA$43.00 - CA$56.00
CA$43.00 - CA$56.00
CA$43.00

SVBONY SV231 Fringe Killer Color Correction Filter

Options available

Reduces violet fringing (chromatic aberration) in achromatic refractors Standard 1.25" filter threads for universal compatibility Blocks IR wavele...

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CA$43.00 - CA$56.00
CA$43.00 - CA$56.00
CA$43.00 - CA$56.00
CA$43.00
CA$126.00 - CA$168.00
CA$126.00 - CA$168.00
CA$126.00 - CA$168.00
CA$126.00

SVBONY SV240 Near-Infrared Multi-Narrowband Light Pollution Filter

Options available

Designed for urban astrophotography with one-shot color cameras Passes H-Alpha, OIII, H-Beta, and Near-Infrared (NIR) wavelengths Peak transmittan...

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CA$126.00 - CA$168.00
CA$126.00 - CA$168.00
CA$126.00 - CA$168.00
CA$126.00
SVBONY SV260 5-Bandpass Light Pollution Filter - 2"
SVBONY SV260 5-Bandpass Light Pollution Filter - 2"
CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00

SVBONY SV260 5-Bandpass Light Pollution Filter - 2"

SV-W9194A

5-Bandpass broadband light pollution filter 2-inch size with M48x0.75 thread Over 90% peak transmittance for high signal OD4 blocking of key light...

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CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00
SVBONY UHC Light Pollution Filter
CA$34.00 - CA$70.00
CA$34.00 - CA$70.00
CA$34.00 - CA$70.00
CA$34.00

SVBONY UHC Ultra High Contrast Light Pollution Filter

Options available

Reduces light pollution from artificial lighting Enhances contrast for emission nebulae Available in 1.25", 2", and Canon EOS-C formats Durable al...

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CA$34.00 - CA$70.00
CA$34.00 - CA$70.00
CA$34.00 - CA$70.00
CA$34.00
SVBONY UV IR-Cut Telescope Filter
CA$22.00 - CA$25.00
CA$22.00 - CA$25.00
CA$22.00 - CA$25.00
CA$22.00

SVBONY UV IR-Cut Filter

Options available
9 variants in stock

Blocks unwanted Ultraviolet (UV) and Infrared (IR) wavelengths Standard 2-inch filter threads for wide compatibility Improves image contrast and c...

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CA$22.00 - CA$25.00
CA$22.00 - CA$25.00
CA$22.00 - CA$25.00
CA$22.00
Tele Vue BandMate H-Beta Filter
CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00

Tele Vue BandMate H-Beta Filter

Options available

Filter Type: Hydrogen-Beta (Hβ) Narrowband Available Sizes: 1.25" and 2" Mounted Primary Targets: Horsehead Nebula, California Nebula Manufacturin...

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CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00
CA$204.00 - CA$450.00
CA$204.00 - CA$450.00
CA$204.00 - CA$450.00
CA$204.00

Tele Vue BandMate Nebustar Filter

Options available
1 variants in stock

Unique Narrowband Design: Transmits both Hβ and OIII emission lines in a single, targeted passband for maximum contrast. Blocks Red Wavelengths:...

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CA$204.00 - CA$450.00
CA$204.00 - CA$450.00
CA$204.00 - CA$450.00
CA$204.00
Tele Vue BandMate OIII Filter
CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00

Tele Vue BandMate OIII Filter

Options available

Isolates doubly ionized oxygen (OIII) emission lines Dramatically increases contrast on planetary nebulae and supernova remnants Manufactured by A...

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CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00 - CA$364.00
CA$200.00
Wanderer Astro ND Filter for WandererCover
CA$7.00 - CA$13.00
CA$7.00 - CA$13.00
CA$7.00 - CA$13.00
CA$7.00

Wanderer Astro ND Filter for WandererCover

Options available

Available in 7 sizes from 80mm to 240mm Designed for WandererCover V4-EC and V4-EC IR Enables Calibrated Flat Frames with Sensitive Cameras Reduce...

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CA$7.00 - CA$13.00
CA$7.00 - CA$13.00
CA$7.00 - CA$13.00
CA$7.00
CA$660.00 - CA$660.00
CA$660.00
CA$660.00 - CA$660.00
CA$660.00

William Optics STC Astro Duo-Narrowband Filter

WO-YF-STC-ADN

Dual-Bandpass for H-Alpha and Oxygen-III Suppresses Urban Light Pollution Ion Beam-Assisted Deposition (IBAD) Coatings High Durability and Easy-to...

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CA$660.00 - CA$660.00
CA$660.00
CA$660.00 - CA$660.00
CA$660.00
CA$328.00 - CA$328.00
CA$328.00
CA$328.00 - CA$328.00
CA$328.00

William Optics STC Ultra Layer Astro Multispectra Filter - 48mm

WO-YF-STC-M48

48mm (M48) Filter Size Multi-Bandpass Light Pollution Suppression Passes H-α, H-β, and OIII Emission Lines Schott B270 Optical Glass Substrate STC...

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CA$328.00 - CA$328.00
CA$328.00
CA$328.00 - CA$328.00
CA$328.00
CA$26.00 - CA$69.00
CA$26.00 - CA$69.00
CA$26.00 - CA$69.00
CA$26.00

ZWO AR Protective Window

Options available
5 variants in stock

Protects camera sensor from dust and humidity 21mm diameter for specific ZWO camera models High-transmission Anti-Reflection (AR) coatings 1/4λ su...

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CA$26.00 - CA$69.00
CA$26.00 - CA$69.00
CA$26.00 - CA$69.00
CA$26.00
CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00

ZWO CH4 Methane Filter - 20nm 1.25"

ZWO-CH4
3 in stock

Reveals high-altitude detail on Jupiter and Saturn 20nm bandpass centered on the methane absorption line Standard 1.25" (31.75mm) threaded cell Re...

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CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$139.00
CA$139.00
CA$139.00 - CA$239.00
CA$139.00 - CA$239.00
CA$139.00 - CA$239.00
CA$139.00

ZWO Duo-Band Filter

Options available
7 variants in stock

Passes H-Alpha (15nm) and OIII (35nm) Wavelengths Designed for One-Shot Color (OSC) Cameras 1.25" Threaded Cell Over 80% Ha & 90% OIII Transmi...

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CA$139.00 - CA$239.00
CA$139.00 - CA$239.00
CA$139.00 - CA$239.00
CA$139.00
CA$40.00 - CA$40.00
CA$40.00
CA$40.00 - CA$40.00
CA$40.00

ZWO IR 850nm Pass Filter – 1.25"

ZWO-850IR1-25
2 in stock

Passes Infrared Light > 850nm Dramatically Steadies Planetary Views in Poor Seeing Enables Daylight Planetary and Lunar Imaging Standard 1.25" ...

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CA$40.00 - CA$40.00
CA$40.00
CA$40.00 - CA$40.00
CA$40.00
CA$26.00 - CA$26.00
CA$26.00
CA$26.00 - CA$26.00
CA$26.00

ZWO IR-Cut Protective Window

Options available
1 variants in stock

21 mm diameter protective window for select ZWO cameras Integrated UV/IR-Cut filter maintains natural color balance 1/4 λ surface flatness preserv...

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CA$26.00 - CA$26.00
CA$26.00
CA$26.00 - CA$26.00
CA$26.00
CA$207.00 - CA$419.00
CA$207.00 - CA$419.00
CA$207.00 - CA$419.00
CA$207.00

ZWO LRGB Optimized Filters

Options available
3 variants in stock

1.25" (31.75mm) Threaded Filter Set Greater than 92% Transmission at Passband Balanced 1:1:1 RGB Exposure Weighting 1/4 Wavefront Polished Optical...

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CA$207.00 - CA$419.00
CA$207.00 - CA$419.00
CA$207.00 - CA$419.00
CA$207.00
CA$517.00 - CA$979.00
CA$517.00 - CA$979.00
CA$517.00 - CA$979.00
CA$517.00

ZWO Narrowband Filter Set - 7nm H-alpha, OIII & SII

Options available
1 variants in stock

Includes 1.25" H-alpha, OIII, and SII filters 7nm bandpass for high-contrast imaging Ideal for creating "Hubble Palette" images Fine-optically pol...

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CA$517.00 - CA$979.00
CA$517.00 - CA$979.00
CA$517.00 - CA$979.00
CA$517.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00

ZWO Narrowband H-alpha Filter - 7nm

Options available

Isolates Hydrogen-Alpha light at a 7nm bandpass Standard 1.25" threaded metal cell Blocks light pollution and moonlight for extreme contrast Multi...

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CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00

ZWO Narrowband OIII Filter - 7nm

Options available
2 variants in stock

7nm Bandpass at OIII Emission Line Isolates Planetary Nebulae and Supernova Remnants Standard 1.25" Threaded Filter Cell 1/4 Wave Optical Substrat...

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CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00

ZWO Narrowband SII Filter - 7nm

Options available
2 variants in stock

Isolates the 672nm Sulfur-II emission line 7nm bandpass for high-contrast imaging Standard 1.25" threaded metal cell 1/4 wave polished substrate w...

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CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00 - CA$349.00
CA$181.00
CA$40.00 - CA$69.00
CA$40.00 - CA$69.00
CA$40.00 - CA$69.00
CA$40.00

ZWO UV/IR CUT Filter

Options available
40 variants in stock

Threads into standard 1.25" filter holders and nosepieces Blocks unwanted ultraviolet (UV) and infrared (IR) wavelengths Functions as a primary Lu...

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CA$40.00 - CA$69.00
CA$40.00 - CA$69.00
CA$40.00 - CA$69.00
CA$40.00

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.