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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$735.00 - CA$2,695.00
CA$735.00 - CA$2,695.00
CA$735.00 - CA$2,695.00
CA$735.00

Chroma LRGB Filter Set

Options available

Luminance, Red, Green, and Blue astronomy filter set Filters designed for use with CCD and for f/4.0 or slower No reflections leading to image dist...

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CA$735.00 - CA$2,695.00
CA$735.00 - CA$2,695.00
CA$735.00 - CA$2,695.00
CA$735.00
CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00

Chroma Luminance Filter

Options available

Luminance filter for enhancing color rendering with RGB set Filters designed for use with CCD and for f/4.0 or slower No reflections leading to ima...

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CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00

Chroma OIII Filter - 3nm

Options available

Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when...

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CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00
CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00

Chroma OIII Filter - 5nm

Options available

Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when...

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CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00
CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00

Chroma OIII Filter - 8nm

Options available

Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when...

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CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00

Chroma OIII Filter Optimized for f/3 - 3nm

Options available

Chroma’s OIII filters isolate the 500.7nm primary emission line of doubly ionized oxygen. After H-alpha, this is the next most common emission when...

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CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00

Chroma R-Bessel Filter

Options available

Red photometric filter in UVBRI series Filters designed for use with CCD and for f/4.0 or slower No reflections leading to image distortions or ""b...

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CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00
CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00

Chroma Red Filter

Options available

Red filter for color rendering with RGB set Filters designed for use with CCD and for f/4.0 or slower No reflections leading to image distortions o...

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CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00 - CA$700.00
CA$210.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00

Chroma SII Filter - 3nm

Options available

SII filters isolate the spectral emission of singly ionized sulfur atoms, also common in nebulae. Emission is at two lines occurring as a doublet, ...

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CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00
CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00

Chroma SII Filter - 5nm

Options available

SII filters isolate the spectral emission of singly ionized sulfur atoms, also common in nebulae. Emission is at two lines occurring as a doublet, ...

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CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00 - CA$1,932.00
CA$644.00
CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00

Chroma SII Filter - 8nm

Options available

SII filters isolate the spectral emission of singly ionized sulfur atoms, also common in nebulae. Emission is at two lines occurring as a doublet, ...

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CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00 - CA$1,162.00
CA$385.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00

Chroma SII Filter Optimized for f/3 - 3nm

Options available

SII filters isolate the spectral emission of singly ionized sulfur atoms, also common in nebulae. Emission is at two lines occurring as a doublet, ...

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CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00 - CA$2,170.00
CA$805.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00

Chroma U-Bessel Filter

Options available

UV photometric filter in UVBRI series Filters designed for use with CCD and for f/4.0 or slower No reflections leading to image distortions or ""ba...

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CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00
CA$1,645.00 - CA$4,795.00
CA$1,645.00 - CA$4,795.00
CA$1,645.00 - CA$4,795.00
CA$1,645.00

Chroma UBVRI Filter Set

Options available

UBVRI filter set for photometric imaging Filters designed for use with CCD and for f/4.0 or slower No reflections leading to image distortions or "...

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CA$1,645.00 - CA$4,795.00
CA$1,645.00 - CA$4,795.00
CA$1,645.00 - CA$4,795.00
CA$1,645.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00

Chroma V-Bessel Filter

Options available

Green (Visible) photometric filter in UVBRI series Filters designed for use with CCD and for f/4.0 or slower No reflections leading to image distor...

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CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00 - CA$1,015.00
CA$385.00
Sold out
CA$48.00 - CA$48.00
CA$48.00
CA$48.00 - CA$48.00
CA$48.00

David Astro Planetary Color Filter Kit with Case - 1.25"

DAV-CF-1.25

Filter No.12 Filter No.21 Filter No.23A Filter No.56 Filter No.82 Moon & Sky filter

CA$48.00 - CA$48.00
CA$48.00
CA$48.00 - CA$48.00
CA$48.00
Sold out
CA$28.00 - CA$28.00
CA$28.00
CA$28.00 - CA$28.00
CA$28.00

David Astro Variable Polarizing Filter - 1.25"

DAV-VPOL-1.25
Only 3 left!

The Variable Polarizing Filter is an essential tool for astronomical observing, designed to enhance your viewing experience by reducing glare and c...

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CA$28.00 - CA$28.00
CA$28.00
CA$28.00 - CA$28.00
CA$28.00
Daystar 2" UV/IR Filter
CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00

Daystar 2" UV/IR Filter

DAY-DSIUV2

2" Barrel Size Blocks Ultraviolet (UV) and Infrared (IR) Wavelengths Passes the Full Visible Spectrum Functions as an Essential Luminance (L) Filt...

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CA$175.00 - CA$175.00
CA$175.00
CA$175.00 - CA$175.00
CA$175.00
Explore Scientific 2" Variable Polarizing Filter
CA$252.00 - CA$252.00
CA$252.00
CA$252.00 - CA$252.00
CA$252.00

Explore Scientific 2" Variable Polarizing Filter

ES-310250

2" Filter Barrel Size Continuously Variable Brightness Ideal for Lunar, Planetary, and Solar Observing Neutral Gray Color Rendition Stackable with...

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CA$252.00 - CA$252.00
CA$252.00
CA$252.00 - CA$252.00
CA$252.00
Explore Scientific Dark-Sky Filter 77mm Slim
CA$252.00 - CA$252.00
CA$252.00
CA$252.00 - CA$252.00
CA$252.00

Explore Scientific Dark-Sky Filter 77mm Slim

ES-310260

77mm Standard Filter Thread Slim Profile Prevents Vignetting Optimized for Wide-Angle Lenses Suppresses Sodium Vapor Streetlight Glow Enhances Con...

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CA$252.00 - CA$252.00
CA$252.00
CA$252.00 - CA$252.00
CA$252.00
CA$153.99 - CA$168.00
CA$153.99 - CA$168.00
CA$153.99 - CA$168.00
CA$153.99

Explore Scientific Nebula Filter CLS - 1.25"

Options available

City Light Suppression (CLS) Filter Enhances Contrast for Deep-Sky Objects Available in 1.25" and 2" Sizes Ideal for Viewing Nebulae and Galaxies ...

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CA$153.99 - CA$168.00
CA$153.99 - CA$168.00
CA$153.99 - CA$168.00
CA$153.99
Explore Scientific Nebula Filter H-Alpha 1.25-inch 12nm
CA$224.00 - CA$224.00
CA$224.00
CA$224.00 - CA$224.00
CA$224.00

Explore Scientific Nebula Filter H-Alpha 1.25-inch 12nm

ES-310135

Targets Hydrogen-Alpha emission nebulae 12nm bandpass for astrophotography 1.25-inch standard filter size Drastically improves contrast under ligh...

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CA$224.00 - CA$224.00
CA$224.00
CA$224.00 - CA$224.00
CA$224.00
Explore Scientific Nebula Filter H-Alpha 2-inch 12nm
CA$350.00 - CA$350.00
CA$350.00
CA$350.00 - CA$350.00
CA$350.00

Explore Scientific Nebula Filter H-Alpha 2-inch 12nm

ES-310130

Isolates the Hydrogen-alpha emission line at a 12nm bandpass Standard 2-inch filter format for modern focusers and filter wheels Dramatically incr...

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CA$350.00 - CA$350.00
CA$350.00
CA$350.00 - CA$350.00
CA$350.00
Explore Scientific Nebula Filter H-Alpha 2-inch 7nm
CA$420.00 - CA$420.00
CA$420.00
CA$420.00 - CA$420.00
CA$420.00

Explore Scientific Nebula Filter H-Alpha 2-inch 7nm

ES-310140

7nm H-Alpha Bandpass 2-inch Filter Format Isolates Hydrogen Emission Nebulae Blocks Urban Light Pollution Includes Individual Test Report Descr...

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CA$420.00 - CA$420.00
CA$420.00
CA$420.00 - CA$420.00
CA$420.00

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.