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H-Alpha & CaK Filters

A solar filter module turns a telescope you already own into a hydrogen-alpha instrument. An etalon at the front, a blocking filter at the back, and a suitable refractor between them gives you prominences and surface detail without buying a second dedicated telescope. David Astro carries solar modules in Canada, held in Canadian stock.

Not every telescope is suitable, and aperture and focal ratio limits are safety-relevant as well as performance-relevant. Tell us your telescope and we will confirm compatibility before anything ships.

Filters

CA$481.00 - CA$481.00
CA$481.00
CA$481.00 - CA$481.00
CA$481.00

Antlia Imaging Herschel Wedge with CaK 3nm Filter - 1.25"

ANT-CAK-WEDGE
1 in stock

Antlia Imaging Herschel Wedge with 35mm Prism and 1.25'' Cak 3nm Solar Filter The Antlia Solar Wedge (Herschel Wedge design) replaces the standard...

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CA$481.00 - CA$481.00
CA$481.00
CA$481.00 - CA$481.00
CA$481.00
CA$415.00 - CA$415.00
CA$415.00
CA$415.00 - CA$415.00
CA$415.00

Baader Calcium GEN-II Filter - 1.25"

BAA-2961590

Calcium GEN-II Solar Filter 1.25" Barrel Size Reveals Chromospheric Detail Camera-Use Only (Not for Visual) Requires Full-Aperture Pre-Filter D...

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CA$415.00 - CA$415.00
CA$415.00
CA$415.00 - CA$415.00
CA$415.00
CA$459.00 - CA$2,416.00
CA$459.00 - CA$2,416.00
CA$459.00 - CA$2,416.00
CA$459.00

Baader D-ERF Energy Rejection Filter - 75-180mm

Options available

Full-aperture solar energy rejection filter Required for use with rear-mounted H-alpha etalon systems Advanced, hard dielectric IR-cut coatings Pr...

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CA$459.00 - CA$2,416.00
CA$459.00 - CA$2,416.00
CA$459.00 - CA$2,416.00
CA$459.00
Baader Planetarium D-ERF Energy Rejection Filter - 290mm Aperture, 20mm Thickness
CA$8,008.00 - CA$8,008.00
CA$8,008.00
CA$8,008.00 - CA$8,008.00
CA$8,008.00

Baader Planetarium D-ERF Energy Rejection Filter - 290mm Aperture, 20mm Thickness

BAA-2965000D

290mm Clear Aperture 20mm Thick Glass Substrate IR-Cut Dielectric Coating Pre-Filter for H-Alpha Solar Systems Description FAQ Specifications I...

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CA$8,008.00 - CA$8,008.00
CA$8,008.00
CA$8,008.00 - CA$8,008.00
CA$8,008.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00

Daystar Calcium Quark Solar Filter

DAY-DSZCH

Targets the 3968.5Å Calcium H-line Wavelength All-in-One Eyepiece-Style Solar Filter Optimized for F/7 to F/30 Refractor Telescopes Integrated 25m...

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CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00

Daystar Camera Quark Chromosphere Solar Filter

Options available

Transforms Canon or Nikon SLR lenses into a Hydrogen-Alpha solar telescope Integrated, H-Alpha optimized telecentric Barlow lens USB-powered, heat...

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CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00

Daystar Camera Quark Prominence Solar Filter

Options available

Transforms Canon or Nikon SLR lenses into a Hydrogen-Alpha solar telescope Optimized for high-contrast views of solar prominences Internal Fabry-P...

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CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00
Daystar Combo Combo Kit - Barlow Set (2.8X & 4.3X)
CA$699.00 - CA$3,493.00
CA$699.00 - CA$3,493.00
CA$699.00 - CA$3,493.00
CA$699.00

Daystar Combo Combo Kit

Options available
1 variants in stock

Modular Combo Quark accessory system — choose the kit that fits your setup Two telecentric barlows (2.8X and 4.3X) with 13 internal baffles each T...

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CA$699.00 - CA$3,493.00
CA$699.00 - CA$3,493.00
CA$699.00 - CA$3,493.00
CA$699.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00

Daystar Combo Quark Chromosphere Solar Filter

DAY-DSZCC
1 in stock

Hydrogen-Alpha Solar Filter for Chromosphere Viewing Optimized for Long Focal Ratio Telescopes (f/15+) All-in-One, Eyepiece-Sized Design Low-Power...

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CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00

Daystar Combo Quark Prominence Solar Filter

DAY-DSZCP

Optimized for Solar Prominences Designed for Telescopes from f/15 to f/30 All-In-One, Eyepiece-Style Design Powered by Standard 5V USB Requires Of...

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CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$770.00 - CA$2,303.00
CA$770.00 - CA$2,303.00
CA$770.00 - CA$2,303.00
CA$770.00

Daystar Energy Rejection Filter for Refractor - 80-150mm ERF Glass

Options available

Full-aperture solar energy rejection filter for refractors Available in 80mm, 100mm, 130mm, and 150mm clear apertures Rejects harmful UV and IR ra...

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CA$770.00 - CA$2,303.00
CA$770.00 - CA$2,303.00
CA$770.00 - CA$2,303.00
CA$770.00
CA$770.00 - CA$1,673.00
CA$770.00 - CA$1,673.00
CA$770.00 - CA$1,673.00
CA$770.00

Daystar Energy Rejection Filter for SCT - 63-125mm Off-Axis ERF Glass

Options available

Off-axis energy rejection filter (ERF) for Schmidt-Cassegrain Telescopes Safely isolates a smaller aperture for high-contrast solar viewing Availa...

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CA$770.00 - CA$1,673.00
CA$770.00 - CA$1,673.00
CA$770.00 - CA$1,673.00
CA$770.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00

Daystar Magnesium Quark Solar Filter

DAY-DSZMG

Observe the unique Magnesium I (Mg I) solar spectral line All-in-one design fits standard 1.25" diagonals Integrated 4.2X telecentric Barlow lens ...

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CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$2,093.00 - CA$2,093.00
CA$2,093.00
CA$19,586.00 - CA$19,586.00
CA$19,586.00
CA$19,586.00 - CA$19,586.00
CA$19,586.00

Daystar Quantum Calcium II H-Line Solar Filter - 5Å PE Grade

DAY-CH5AUNI

Targets the Calcium II H-Line Emission Optimized for Visual and Imaging Use Reveals Lower Chromospheric Detail Produces a High-Contrast Violet Ima...

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CA$19,586.00 - CA$19,586.00
CA$19,586.00
CA$19,586.00 - CA$19,586.00
CA$19,586.00
CA$25,186.00 - CA$25,186.00
CA$25,186.00
CA$25,186.00 - CA$25,186.00
CA$25,186.00

Daystar Quantum Calcium II K Solar Filter - 2Å PE Grade

DAY-CK2AUNI

Targets the Calcium II K-line at 393.3nm 2Å Bandpass for high-contrast chromospheric detail PE (Professional Edition) Grade for research applicati...

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CA$25,186.00 - CA$25,186.00
CA$25,186.00
CA$25,186.00 - CA$25,186.00
CA$25,186.00
CA$16,786.00 - CA$50,386.00
CA$16,786.00 - CA$50,386.00
CA$16,786.00 - CA$50,386.00
CA$16,786.00

Daystar Quantum H-alpha Solar Filter

Options available

Bandpass options from 0.8Å down to 0.3Å for specific solar targets Live LCD readout of the precise wavelength output, accurate to 0.1Å Red/blue pu...

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CA$16,786.00 - CA$50,386.00
CA$16,786.00 - CA$50,386.00
CA$16,786.00 - CA$50,386.00
CA$16,786.00
Daystar Quantum H-alpha Solar Filter - SE Grade - 0.7-0.9Å
CA$7,273.00 - CA$12,593.00
CA$7,273.00 - CA$12,593.00
CA$7,273.00 - CA$12,593.00
CA$7,273.00

Daystar Quantum H-alpha Solar Filter - SE Grade

Options available

Choice of 0.7-0.9Å or 0.3-0.5Å Tunable Hydrogen-Alpha Bandpass SE (Standard Edition) Grade for Amateur and Academic Use Live LCD Wavelength Readou...

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CA$7,273.00 - CA$12,593.00
CA$7,273.00 - CA$12,593.00
CA$7,273.00 - CA$12,593.00
CA$7,273.00
CA$25,193.00 - CA$25,193.00
CA$25,193.00
CA$25,193.00 - CA$25,193.00
CA$25,193.00

Daystar Quantum Helium D3 Solar Filter - 0.3Å PE Grade

DAY-HeD.3PE

Observes in the rare Helium D3 line at 5875.61Å Ultra-narrow 0.3Å bandpass for maximizing contrast Professional Edition (PE) grade for research-le...

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CA$25,193.00 - CA$25,193.00
CA$25,193.00
CA$25,193.00 - CA$25,193.00
CA$25,193.00
CA$25,186.00 - CA$25,186.00
CA$25,186.00
CA$25,186.00 - CA$25,186.00
CA$25,186.00

Daystar Quantum Sodium D Solar Filter - 0.4Å PE Grade

DAY-NAD.4UNI

Targets the Sodium D emission line at 5895.9Å Ultra-narrow 0.4Å bandpass for high-contrast views Professional Edition (PE) grade for research appl...

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CA$25,186.00 - CA$25,186.00
CA$25,186.00
CA$25,186.00 - CA$25,186.00
CA$25,186.00
CA$1,799.00 - CA$1,799.00
CA$1,799.00
CA$1,799.00 - CA$1,799.00
CA$1,799.00

Daystar Quark Chromosphere Solar Filter

DAY-DSZ4C
5 in stock

All-In-One Hydrogen-Alpha Solar Filter System Designed for Chromosphere (Solar Surface) Detail Integrated, H-Alpha Optimized Telecentric Barlow St...

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CA$1,799.00 - CA$1,799.00
CA$1,799.00
CA$1,799.00 - CA$1,799.00
CA$1,799.00
CA$3,633.00 - CA$3,633.00
CA$3,633.00
CA$3,633.00 - CA$3,633.00
CA$3,633.00

Daystar Quark Combo Gemini Chrom/Prom Switchable Solar Filter

DAY-DSZGC

Instantly Switchable Prominence & Chromosphere Views Contains Two Internal Fabry-Perot Etalon Filters Optimized for Telescopes from f/15 to f/...

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CA$3,633.00 - CA$3,633.00
CA$3,633.00
CA$3,633.00 - CA$3,633.00
CA$3,633.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00

Daystar Quark for Questar Chromosphere Solar Filter

DAY-DSZQC

All-In-One Hydrogen-Alpha Solar Filter Tuned for Chromosphere (Surface) Detail Designed Exclusively for Questar Telescopes USB-Powered for Field U...

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CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00

Daystar Quark for Questar Prominence Solar Filter

DAY-DSZQP

Transforms a Questar telescope into a Hydrogen-alpha solar telescope Prominence model optimized for high-contrast views of solar limb activity All...

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CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$1,813.00 - CA$1,813.00
CA$1,813.00
CA$3,633.00 - CA$3,633.00
CA$3,633.00
CA$3,633.00 - CA$3,633.00
CA$3,633.00

Daystar Quark Gemini Chrom/Prom Switchable Solar Filter

DAY-DSZ4G
1 in stock

Dual Switchable H-alpha Etalons: Instantly select a ≤0.5Å bandpass for chromosphere detail or a ≥0.6Å bandpass for bright prominences. Integrate...

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CA$3,633.00 - CA$3,633.00
CA$3,633.00
CA$3,633.00 - CA$3,633.00
CA$3,633.00

How a Solar Filter Module Works

Two components do the work. The etalon defines a very narrow passband around the hydrogen-alpha line; the blocking filter removes everything the etalon lets through elsewhere in the spectrum, including the infrared that would otherwise reach your eye.

  • Front-mounted etalons: Fitted ahead of the objective, with a maximum aperture and minimum focal ratio specified by the manufacturer. Exceeding either degrades performance and can cause heat damage.
  • Blocking filters: Fitted at the eyepiece end, sized by their clear aperture. The size determines usable field and whether full-disc imaging is possible.
  • Tuning: Tilt or pressure adjustment shifts the passband to favour disc detail or limb prominences during a session.
  • Focal ratio requirements: Etalons perform best within a specified range, commonly around f/7 and slower. Faster telescopes may need a telecentric amplifier to present the correct light cone.
  • Telecentric amplifiers: Present parallel light to the etalon rather than a converging cone, which is what allows a fast refractor to be used correctly.
  • Double-stacking: A second etalon narrows the band further for markedly better surface contrast, with a corresponding loss of brightness.

Why Choose David Astro for Solar Modules

Compatibility here is not a matter of whether the parts thread together. It is a safety and performance specification.

  • Telescope suitability verified: We check your aperture and focal ratio against the module's stated limits before supplying anything, because exceeding them risks thermal damage.
  • Refractors only, and we say so: Front-mounted etalons are for unobstructed refractors. We will not supply a module for a reflector or catadioptric where concentrated heat inside the tube is a hazard.
  • Blocking filter sized to your intent: Full-disc imaging with a larger sensor needs a larger blocking filter, and we check that against your camera.
  • Authorized dealer: Genuine equipment with full manufacturer warranty, which is a safety requirement in solar filtration.
  • Ships from Canada: No duties or brokerage fees for Canadian buyers.

Solar Modules in Canada — Frequently Asked Questions

Can I fit a solar module to my telescope?
Only if it is an unobstructed refractor within the module's specified aperture and focal ratio range. Tell us the exact telescope and we will confirm before you order.
Why does focal ratio matter for an etalon?
An etalon's passband shifts with the angle of incoming light. A converging cone from a fast telescope smears the passband and reduces contrast. A telecentric amplifier restores a parallel cone.
What blocking filter size do I need?
Larger blocking filters pass a wider field. Visual use and small sensors are generally fine with a smaller one; full-disc imaging on a larger sensor needs more clear aperture.
Is a module cheaper than a dedicated solar telescope?
Often, if you already own a suitable refractor, and it gives you a telescope that does both jobs. A dedicated instrument is optimized for the wavelength and is simpler to set up.

Converting a refractor for solar?

Send us the exact telescope and we will confirm compatibility and specify the module. Canadian stock, worldwide shipping.