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
Player One LRGB Filter S-series
LRGB filter set for monochrome astrophotography Available in 1.25" and 2" sizes (2" round mounted for larger sensors) Constructed from high-qualit...
View full detailsPlayer One OIII 7nm Narrowband Filter S-series
Oxygen-III (OIII) 7nm Narrowband Filter Available in 1.25" and 2" Sizes for Narrowband Astrophotography High-Transmission, Multi-Layer Coatings Hi...
View full detailsPlayer One SII 7nm Narrowband Filter S-series
Sulfur-II (SII) Narrowband Filter 7nm Narrowband Passband Available in 1.25" and 2" Mounted Formats Optimized for High-Contrast Astrophotography A...
View full detailsPlayer One UV/IR-Cut Anti-Halo Filter - 2"
Blocks unwanted Ultraviolet (UV) and Infrared (IR) wavelengths Features advanced anti-halo coatings to minimize reflections Standard 2" filter cel...
View full detailsPlayer One UV/IR-Cut S-Series Filter - 1.25"
Corrects Color Balance for Color Cameras Blocks Unwanted Ultraviolet (UV) and Infrared (IR) Light Enhances Contrast for Lunar and Solar Imaging Hi...
View full detailsPlayer One UVenus UV-Pass Filter E-series - 1.25"
Reveals Cloud Detail on Venus UV-Pass Band Optimized for Planetary Imaging E-Series High-Quality Optical Glass Substrate 1.25" Mounted Filter Form...
View full detailsQHYCCD 1200-1800nm SWIR Filter
1200-1800nm SWIR Bandpass Designed for QHYCCD InGaAs Cameras Compatible with QHY990 Series Description FAQ Specifications In the Box Warranty ...
View full detailsQHYCCD Expansion Kit for QHY5III462C
This kit contains a methane filter, an AllSky lens and a lens adapter. It's made for the QHY5III462C camera only.
SVBONY CLS Light Pollution Broadband Filter
Broadband Light Pollution Suppression Effectively Blocks Sodium and Mercury Vapor Streetlights High Transmission on Key Nebula Emission Lines Opti...
View full detailsSVBONY Linear Polarizer Filter
Reduces light transmission to a comfortable 13% for lunar viewing Standard 1.25-inch barrel size fits most eyepieces and accessories Threads into ...
View full detailsSVBONY Moon Filter
Reduces glare for comfortable lunar and planetary observing Fits any standard 1.25" eyepiece or accessory Standard M28.5x0.6 filter threads Enhanc...
View full detailsSVBONY SV115 18nm OIII Narrowband Filter
2-inch diameter filter for standard eyepieces and accessories 18nm bandpass isolates key Oxygen-III emission lines 90% peak transmittance at 495.9...
View full detailsSVBONY SV128 Variable Polarizing Filter
Available in 1.25" and 2" barrel sizes Continuously variable light transmission Reduces glare for enhanced lunar and planetary contrast Constructe...
View full detailsSVBONY SV132 25nm H-Beta Narrowband Filter
Targets the 486nm Hydrogen-Beta emission line 25nm bandpass for enhanced contrast 80% peak transmittance at the H-Beta wavelength Blocks Mercury (...
View full detailsSVBONY SV139 ND0.6 Neutral Density Moon Filter - 1.25"
Reduces lunar glare with a fixed ND0.6 optical density Transmits a neutral 25% of incoming light Standard 1.25-inch barrel fits most eyepieces Mul...
View full detailsSVBONY SV139 ND0.9 Neutral Density Moon Filter - 1.25"
Reduces lunar brightness by ~87.5% (ND0.9) Fits any standard 1.25-inch eyepiece or accessory Neutral density filter preserves true color balance F...
View full detailsSVBONY SV139 ND1.2 Neutral Density Moon Filter - 1.25"
Reduces Lunar Glare with ND1.2 Density Transmits 6.25% of Incoming Light Standard 1.25-inch Barrel Threads Fully Multi-Coated Optical Glass Neutra...
View full detailsSVBONY SV139 ND3.0 Neutral Density Moon Filter - 1.25"
ND3.0 Neutral Density Filter Standard 1.25-inch Barrel Size Transmits 0.1% of Incoming Light (10-Stop / 1000× Reduction) Ideal for Herschel Solar ...
View full detailsSVBONY SV155 7-Piece Telescope Filter Set - 1.25"
7-Piece Filter Set Includes Moon, CPL, and 5 Color Filters Standard 1.25-inch Barrel Size M28.5*0.6 Filter Threads 2mm Thick Optical Glass Desc...
View full detailsSVBONY SV164 Dark Filter for CCD and CMOS Cameras
2-inch Filter Size Standard M48x0.75 Threads Enables Automated Dark Frame Capture 1mm Filter Thickness Durable Anodized Aluminum Cell Descripti...
View full detailsSVBONY SV183 685nm IR Pass Filter
685nm Infrared (IR) Pass Filter Standard 1.25" Threaded Barrel Transmits >95% of light from 673nm to 1100nm Blocks Visible Light with OD2 Block...
View full detailsSVBONY SV220 3nm H-Alpha & OIII Dual Narrowband Filter
3nm Dual-Bandpass: Isolates H-Alpha (656.3 nm) and OIII (500.7 nm) emission lines with extreme prejudice against light pollution. ≥85% Peak Tran...
View full detailsSVBONY SV227 H-Alpha 5nm Narrowband Filter - 2"
Isolates the 656.3nm H-Alpha wavelength Aggressive 5nm Full Width at Half Maximum (FWHM) bandpass Peak transmittance of ≥90% for high signal throu...
View full detailsSVBONY SV227 OIII 5nm Narrowband Filter - 2"
Isolates the Oxygen III emission line at 500.7nm Extremely narrow 5nm Full Width at Half Maximum (FWHM) bandpass Achieves ≥90% peak light transmit...
View full detailsFilter 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.