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
Optolong Moon & Skyglow Filter
Blocks over 99% of common light pollution emission lines Maintains over 90% average transmission for bright, detailed views λ/4 transmitted wavefr...
Afficher tous les détailsOptolong Night Sky H-Alpha IR Pass Filter
Passes Infrared Light >650nm Blocks Visible Light from 300-570nm Average Transmission >90% 1.85mm Thick Optical Glass Substrate λ/4 Transmit...
Afficher tous les détailsOptolong OIII 18nm Nebula Filter
18nm Bandpass Centered on OIII Emission Lines (500nm) Greater than 80% Average Light Transmission (Tave) Blocks >99% of Major Light Pollution L...
Afficher tous les détailsOptolong OIII 3nm Narrowband Filter
3nm Spectral Bandpass 500nm Central Wavelength (OIII) Ion-Assisted Multi-Layer Coatings Optimized for Monochrome Cameras Available in 2" Mounted o...
Afficher tous les détailsOptolong OIII 6.5nm Narrowband Filter
6.5nm Narrowband OIII Filter Centered on 500nm Wavelength Captures both 495.9nm and 500.7nm Emission Lines Blocks Light Pollution and Skyglow Idea...
Afficher tous les détailsOptolong SII 3nm Narrowband Filter
Isolates the Sulfur-II (SII) emission line for astrophotography Extremely narrow 3nm bandpass for maximum contrast Drastically reduces skyglow and...
Afficher tous les détailsOptolong SII 6.5nm Narrowband Filter
Isolates the Sulfur-II (SII) emission line at 672nm Tight 6.5nm bandpass for maximum contrast Enables imaging in heavily light-polluted skies and ...
Afficher tous les détailsFiltre UHC Optolong
Optolong UHC avec une bande passante plus étroite offre un contraste plus élevé. Ainsi, il est plus adapté à l'environnement urbain où vous souffr...
Afficher tous les détailsFiltre anti-UV/IR Optolong
Le filtre Optolong UV/IR Cut est conçu pour le blocage des longueurs d'onde ultraviolettes et infrarouges afin d'améliorer la netteté de l'image c...
Afficher tous les détailsOptolong Variable Polarizing Filter
Continuously Variable Light Transmission Available in 1.25" and 2" Barrel Sizes Ideal for Lunar, Planetary, and Terrestrial Viewing Reduces Glare ...
Afficher tous les détailsPegasus Astro Indigo Filter Wheel - 7 x 2"
Holds seven 2-inch mounted or 50mm unmounted filters Ultra-thin 19.0mm CNC-milled aluminum body Stepper motor with optical encoders for precise po...
Afficher tous les détailsPegasus Astro LRGB Filter Set - 2"
Complete 4-filter LRGB set for broadband deep-sky imaging Standard 2-inch mounted format for wide compatibility Guaranteed 1/4 wavefront optical p...
Afficher tous les détailsPlayer One Anti-Halo PRO Dual-Band Ha/OIII Filter - 2"
Advanced Halo Suppression: Specifically engineered to eliminate halos around even the brightest stars. Dual-Band Ha+OIII Design: Captures hydrog...
Afficher tous les détailsPlayer One CH4 8nm Filter E-series - 1.25"
Isolates the 8nm methane (CH4) absorption band Standard 1.25″ filter cell format Optimized for modern CMOS and CCD planetary cameras E-series feat...
Afficher tous les détailsPlayer One Extra Filter Drawer Holder - 1.25"
Holds Standard 1.25" Filters M28.5x0.6 Female Threads Compatible with Player One Filter Drawer MAX & MINI Enables Quick Filter Changes Desc...
Afficher tous les détailsPlayer One Extra Filter Drawer Holder - 2"
Holds Standard 2" Mounted Filters M48x0.75 Internal Female Threads Compatible with Player One Filter Drawer MAX Compatible with Player One Filter ...
Afficher tous les détailsPlayer One Filter Drawer MAX - 2"
Securely holds standard 2" mounted filters Robust 3-point locking mechanism prevents tilt and flexure Internal M48x0.75 threads for filter mountin...
Afficher tous les détailsPlayer One Filter Drawer MINI
Compact filter drawer system for astrophotography Available in 1.25" and 2" filter sizes Secure metal bead screw locking mechanism prevents tilt D...
Afficher tous les détailsPlayer One Ha 7nm Narrowband Filter S-series
7nm Hydrogen-alpha (Ha) Narrowband Filter Available in 1.25" Threaded Cell and 2" Round Mounted Formats Optimized for Monochrome CMOS/CCD Cameras ...
Afficher tous les détailsPlayer One IR685nm IR-Pass Filter S-series - 1.25"
Passes infrared light with wavelengths greater than 685nm Standard 1.25" filter format for broad compatibility Significantly improves image stabil...
Afficher tous les détailsPlayer One IR850nm IR-Pass Filter S-series - 1.25"
Passes Infrared Light at 850nm Standard 1.25" Filter Size Blocks Visible and Ultraviolet Light High-Quality Optical Glass Substrate Multi-Layer An...
Afficher tous les détailsPlayer 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...
Afficher tous les détailsPlayer 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...
Afficher tous les détailsPlayer One Phoenix Filter Wheel - 5x2"
Accommodates five 2-inch mounted filters Automates filter changes for imaging sequences Designed for LRGB and narrowband astrophotography USB conn...
Afficher tous les détailsFilter 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.