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Optolong

Optolong

Optolong's dual and multi-band filters changed what is possible with a one-shot colour camera under city skies. By passing hydrogen-alpha and oxygen III together and rejecting nearly everything between, they let a colour sensor capture narrowband-like contrast in a single session — no filter wheel, no monochrome workflow, no three-times-longer imaging. David Astro carries Optolong products in Canada, stocked domestically and ready to ship.

Which filter suits you depends on your camera type, focal ratio and target. Tell us all three and we will recommend.

Filters

Optolong Clear Focusing Filter
CA$34.00 - CA$42.00
CA$34.00 - CA$42.00
CA$34.00 - CA$42.00
CA$34.00

Optolong Clear Focusing Filter

Options available
2 variants in stock

Achieve Critical Focus with Dim Stars Transmission >98.5% Across the Visible Spectrum λ/4 Transmitted Wavefront for Image Integrity Parfocal wi...

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CA$34.00 - CA$42.00
CA$34.00 - CA$42.00
CA$34.00 - CA$42.00
CA$34.00
Optolong Clear Sky Light Pollution Filter
CA$139.00 - CA$287.00
CA$139.00 - CA$287.00
CA$139.00 - CA$287.00
CA$139.00

Optolong Clear Sky Light Pollution Filter

Options available

Suppresses common sources of urban light pollution Enhances contrast for deep-sky objects Improves natural color balance in astrophotography Durab...

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CA$139.00 - CA$287.00
CA$139.00 - CA$287.00
CA$139.00 - CA$287.00
CA$139.00
Optolong CLS Light Pollution Filter
CA$77.00 - CA$119.00
CA$77.00 - CA$119.00
CA$77.00 - CA$119.00
CA$77.00

Optolong CLS Light Pollution Filter

Options available

Suppresses common light pollution sources Average transmission greater than 90% on key nebula emission lines Blocks light pollution lines with >...

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CA$77.00 - CA$119.00
CA$77.00 - CA$119.00
CA$77.00 - CA$119.00
CA$77.00
Optolong CLS-CCD Light Pollution Filter
CA$133.00 - CA$223.00
CA$133.00 - CA$223.00
CA$133.00 - CA$223.00
CA$133.00

Optolong CLS-CCD Light Pollution Filter

Options available

Blocks >99% of primary light pollution emission lines Achieves >90% average transmission on key nebula wavelengths Integrated 300-1100nm UV/...

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CA$133.00 - CA$223.00
CA$133.00 - CA$223.00
CA$133.00 - CA$223.00
CA$133.00
CA$474.00 - CA$586.00
CA$474.00 - CA$586.00
CA$474.00 - CA$586.00
CA$474.00

Optolong H-alpha 3nm Narrowband Filter

Options available
1 variants in stock

3nm Bandpass at 656nm Wavelength Maximizes Contrast for Emission Nebulae Extreme Rejection of Light Pollution and Skyglow Ion-Assisted, Anti-Refle...

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CA$474.00 - CA$586.00
CA$474.00 - CA$586.00
CA$474.00 - CA$586.00
CA$474.00
Optolong H-Alpha 7nm Narrowband Filter
CA$223.00 - CA$321.00
CA$223.00 - CA$321.00
CA$223.00 - CA$321.00
CA$223.00

Optolong H-Alpha 7nm Narrowband Filter

Options available
3 variants in stock

Isolates the 656nm Hydrogen-alpha emission line 7nm bandpass for maximum contrast Blocks mercury vapor, sodium vapor, and natural skyglow Ideal fo...

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CA$223.00 - CA$321.00
CA$223.00 - CA$321.00
CA$223.00 - CA$321.00
CA$223.00
Optolong Ha 7nm, OIII 6.5nm & SII 6.5nm Filter Set
CA$651.00 - CA$937.00
CA$651.00 - CA$937.00
CA$651.00 - CA$937.00
CA$651.00

Optolong Ha 7nm, OIII 6.5nm & SII 6.5nm Filter Set

Options available

H-alpha Filter: 7nm Bandpass centered at 656nm Oxygen-III Filter: 6.5nm Bandpass centered at 500nm Sulphur-II Filter: 6.5nm Bandpass Hubble Pa...

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CA$651.00 - CA$937.00
CA$651.00 - CA$937.00
CA$651.00 - CA$937.00
CA$651.00
Optolong Ha, OIII & SII 3nm Narrowband Filter Set
CA$1,344.00 - CA$1,679.00
CA$1,344.00 - CA$1,679.00
CA$1,344.00 - CA$1,679.00
CA$1,344.00

Optolong Ha, OIII & SII 3nm Narrowband Filter Set

Options available

Complete SHO set includes H-alpha, OIII, and SII filters Ultra-narrow 3nm bandpass for maximum contrast Isolates 656nm Ha and 500nm OIII emission ...

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CA$1,344.00 - CA$1,679.00
CA$1,344.00 - CA$1,679.00
CA$1,344.00 - CA$1,679.00
CA$1,344.00
CA$110.00 - CA$161.00
CA$110.00 - CA$161.00
CA$110.00 - CA$161.00
CA$110.00

Optolong IR Pass 685nm Planetary Filter

Options available
3 variants in stock

Passes infrared light above 685nm Achieves greater than 90% peak transmission Blocks wavelengths from 350-1050nm outside the passband 1.85mm thick...

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CA$110.00 - CA$161.00
CA$110.00 - CA$161.00
CA$110.00 - CA$161.00
CA$110.00
CA$251.00 - CA$363.00
CA$251.00 - CA$363.00
CA$251.00 - CA$363.00
CA$251.00

Optolong L-Enhance Filter

Options available
7 variants in stock

Dual-bandpass filter isolates H-Alpha, H-Beta, and OIII emission lines Peak transmission of over 90% for maximum signal Blocks over 99% of light p...

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CA$251.00 - CA$363.00
CA$251.00 - CA$363.00
CA$251.00 - CA$363.00
CA$251.00
CA$796.00 - CA$796.00
CA$796.00
CA$796.00 - CA$796.00
CA$796.00

Optolong L-Extreme + L-Synergy L2 Dual-Combo Filter Set - 2"

OPT-L2-COMBO
3 in stock

Includes L-eXtreme (H-alpha + OIII) and L-Synergy (SII + OIII) filters Enables Hubble Palette (SHO) imaging with one-shot color cameras Captures t...

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CA$796.00 - CA$796.00
CA$796.00
CA$796.00 - CA$796.00
CA$796.00
CA$335.00 - CA$432.00
CA$335.00 - CA$432.00
CA$335.00 - CA$432.00
CA$335.00

Optolong L-Extreme Filter

Options available
9 variants in stock

Narrow dual-bandpass filter for H-Alpha and OIII Blocks >99% of light pollution emission lines Peak transmission of >90% at critical wavelen...

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CA$335.00 - CA$432.00
CA$335.00 - CA$432.00
CA$335.00 - CA$432.00
CA$335.00
CA$362.00 - CA$362.00
CA$362.00
CA$362.00 - CA$362.00
CA$362.00

Optolong L-Para HA/OIII 10nm Filter - 2"

OPT-AS100221
5 in stock

Dual Narrowband H-Alpha & OIII Filter Suppresses Mercury, Sodium & LED Light Pollution Optimized for Fast-Ratio Systems (RASA, HyperStar) ...

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CA$362.00 - CA$362.00
CA$362.00
CA$362.00 - CA$362.00
CA$362.00
CA$419.00 - CA$419.00
CA$419.00
CA$419.00 - CA$419.00
CA$419.00

Optolong L-Pro + UHC Clip Filter Kit

Options available

Two Optolong Clip-in Light Pollution Filters in One Kit L-Pro: Multi-Bandpass Suppression Across 380-750nm UHC: >99% Blocking of Mercury and So...

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CA$419.00 - CA$419.00
CA$419.00
CA$419.00 - CA$419.00
CA$419.00
CA$199.00 - CA$377.00
CA$199.00 - CA$377.00
CA$199.00 - CA$377.00
CA$199.00

Optolong L-Pro Filter

Options available
13 variants in stock

Multi-Bandpass Light Pollution Suppression Effective Spectrum from 380-750nm Maintains Natural Color Balance on Broadband Targets High Transmissio...

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CA$199.00 - CA$377.00
CA$199.00 - CA$377.00
CA$199.00 - CA$377.00
CA$199.00
CA$558.00 - CA$558.00
CA$558.00
CA$558.00 - CA$558.00
CA$558.00

Optolong L-Quad Enhance + L-Para L1 Dual-Combo Filter Set - 2"

OPT-L1-SET
4 in stock

L-Quad Enhance Filter: A quad-bandpass filter designed for balanced RGB color from broadband targets. L-Para L1 Filter: A dual-narrowband filter...

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CA$558.00 - CA$558.00
CA$558.00
CA$558.00 - CA$558.00
CA$558.00
CA$278.00 - CA$278.00
CA$278.00
CA$278.00 - CA$278.00
CA$278.00

Optolong L-Quad Enhance Filter

OPT-14702
4 in stock

Quad-bandpass design for color cameras Suppresses light pollution with OD2-OD4 blocking depth Maintains sharpness with a λ/4 transmitted wavefront...

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CA$278.00 - CA$278.00
CA$278.00
CA$278.00 - CA$278.00
CA$278.00
CA$432.00 - CA$432.00
CA$432.00
CA$432.00 - CA$432.00
CA$432.00

Optolong L-Synergy 7nm SII/OIII Dual Narrowband Filter

OPT-LSYNERGY
3 in stock

Captures Sulfur-II and Oxygen-III Emission Lines Simultaneously Engineered for Hubble Palette (SHO) Imaging with Color Cameras Strict 7nm Bandpass...

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CA$432.00 - CA$432.00
CA$432.00
CA$432.00 - CA$432.00
CA$432.00
CA$404.00 - CA$545.00
CA$404.00 - CA$545.00
CA$404.00 - CA$545.00
CA$404.00

Optolong L-Ultimate Ha/OIII 3nm Filter

Options available
14 variants in stock

Dual 3nm bandpass isolates Hydrogen-alpha and Oxygen-III emission lines Blocks light pollution across the 300-1000nm spectrum Greater than OD4 blo...

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CA$404.00 - CA$545.00
CA$404.00 - CA$545.00
CA$404.00 - CA$545.00
CA$404.00
CA$517.00 - CA$797.00
CA$517.00 - CA$797.00
CA$517.00 - CA$797.00
CA$517.00

Optolong LRGB + H-Alpha 7nm Filter Set

Options available

Complete 5-Filter LRGB and H-Alpha Set 7nm H-Alpha Filter Centered at 656.3nm Blocks 589nm Sodium Light Pollution Line High Transmission for Natur...

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CA$517.00 - CA$797.00
CA$517.00 - CA$797.00
CA$517.00 - CA$797.00
CA$517.00
CA$349.00 - CA$503.00
CA$349.00 - CA$503.00
CA$349.00 - CA$503.00
CA$349.00

Optolong LRGB Filter Set

Options available
9 variants in stock

Complete 4-filter LRGB set for monochrome cameras High average transmission of over 90% for maximum signal Blocks sodium light pollution at 589nm ...

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CA$349.00 - CA$503.00
CA$349.00 - CA$503.00
CA$349.00 - CA$503.00
CA$349.00
CA$931.00 - CA$1,413.00
CA$931.00 - CA$1,413.00
CA$931.00 - CA$1,413.00
CA$931.00

Optolong LRGB, Ha, OIII & SII Filter Set

Options available
3 variants in stock

Complete 7-filter set for monochrome astrophotography Includes Luminance, Red, Green, and Blue broadband filters Includes 3nm Hydrogen-alpha, Oxyg...

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CA$931.00 - CA$1,413.00
CA$931.00 - CA$1,413.00
CA$931.00 - CA$1,413.00
CA$931.00
Optolong Moon & Skyglow Filter
CA$45.00 - CA$67.00
CA$45.00 - CA$67.00
CA$45.00 - CA$67.00
CA$45.00

Optolong Moon & Skyglow Filter

Options available

Blocks over 99% of common light pollution emission lines Maintains over 90% average transmission for bright, detailed views λ/4 transmitted wavefr...

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CA$45.00 - CA$67.00
CA$45.00 - CA$67.00
CA$45.00 - CA$67.00
CA$45.00
Optolong Night Sky H-Alpha IR Pass Filter
CA$111.00 - CA$167.00
CA$111.00 - CA$167.00
CA$111.00 - CA$167.00
CA$111.00

Optolong Night Sky H-Alpha IR Pass Filter

Options available

Passes Infrared Light >650nm Blocks Visible Light from 300-570nm Average Transmission >90% 1.85mm Thick Optical Glass Substrate λ/4 Transmit...

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CA$111.00 - CA$167.00
CA$111.00 - CA$167.00
CA$111.00 - CA$167.00
CA$111.00

The Optolong Filter Range

The line spans broadband light pollution rejection through single-line narrowband, with the dual and triple-band filters being the most widely used.

  • Dual-band filters: Pass Ha and OIII together, which a colour camera's Bayer array separates naturally. The most effective single filter for one-shot colour imaging under light pollution.
  • Narrower dual-band options: Tighter passbands giving higher contrast, best suited to slower focal ratios where the passband does not shift significantly.
  • Broadband light pollution filters: Reject artificial emission lines while passing most of the spectrum, useful for galaxies and star clusters where narrowband would remove the target's own light.
  • Single-line narrowband: Ha, OIII and SII in several bandwidths for monochrome imaging with a filter wheel.
  • LRGB sets: Balanced colour separation filters with UV and IR blocking for monochrome broadband imaging.
  • Sizes and formats: Mounted 1.25 inch and 2 inch, plus 31 mm, 36 mm and unmounted formats for filter wheels and drawers.

Why Choose David Astro for Optolong

Dual-band filters are the highest-value purchase available to a colour imager in a city, provided the bandwidth suits the optics.

  • Focal ratio matched: Very narrow dual-band filters lose performance below roughly f/4 as the passband shifts. We recommend a bandwidth appropriate to your system.
  • Camera type considered: We distinguish clearly between what suits a one-shot colour camera and what suits monochrome, since the right filter differs completely.
  • Spacing accounted for: Filter thickness shifts focus, and we include it in the back-focus calculation supplied with your order.
  • Authorized dealer: Genuine filters with verified coatings and manufacturer warranty, in Canadian stock.
  • Ships from Canada: No duties or brokerage fees for Canadian buyers.

Optolong in Canada — Frequently Asked Questions

Which filter for a colour camera in a city?
A dual-band Ha and OIII filter, almost without exception. It gives the largest single improvement available to a one-shot colour imager under light pollution, on emission nebulae.
Will a dual-band filter help with galaxies?
No. Galaxies emit across the spectrum, so a narrow filter removes their light along with the skyglow. Use a broadband light pollution filter, or better, a darker site.
Does bandwidth matter for my telescope?
Yes below about f/4, where a steep light cone shifts a narrow passband away from the emission line. In that case a slightly wider version performs better despite the looser rejection.
Can I use these with a monochrome camera?
Dual-band filters are designed for colour sensors. With monochrome, use single-line filters in a wheel, which gives better control and higher signal per channel.

Imaging in colour from a bright site?

Tell us your camera and focal ratio and we will recommend the right filter. In Canadian stock, shipped worldwide.