Optolong

Optolong: Precision Astronomy Filters for Astrophotography

Optolong Optics is a Chinese manufacturer specialising in the design and production of high-transmission optical filters for astrophotography. Thanks to interference coatings using magnetron sputtering technology and substrates in high-quality optical glass, Optolong filters deliver precise and repeatable transmission curves — designed to maximise the contrast of emission nebulae and reduce light pollution, whether used with modified cameras or unmodified CMOS sensors.

Narrowband, Dual-Band and Broadband Filters for Every Need

The Optolong range covers all the main requirements of narrowband astrophotography. The L-eXtreme filter (dual-band H-alpha + O-III at 7 nm) and the L-eNhance (dual-band H-alpha + H-beta + O-III) are designed for imaging under light-polluted skies, even with unmodified DSLRs. The L-Ultimate maximises selectivity with an ultra-narrow passband for urban environments. The L-Synergy (S-II + O-III 7 nm) is the choice for the Hubble palette without a separate H-alpha filter.

For those preferring a broadband approach, the L-Pro offers effective light pollution reduction while preserving natural colour balance — available in clip version for Canon APS-C and Sony Full Frame. The L-QEF Quad Enhance and L-PARA complete the range for advanced applications.

What You’ll Find in This Section

Dual-band H-alpha + O-III: L-eXtreme 7 nm, L-eNhance — for nebula imaging under light-polluted skies
Dual-band S-II + O-III: L-Synergy 7 nm — for bichromatic Hubble palette
Ultra-narrowband: L-Ultimate 2" — for heavily light-polluted urban environments
Light pollution reduction: L-Pro (clip Canon APS-C, Sony FF, 1.25" and 2")
Mono-narrowband: H-alpha 7 nm, O-III 6.5 nm, S-II 6.5 nm — in 1.25", 2" and 36 mm
Sets and combos: L-RGB kit (1.25", 2", 36 mm), L-QEF Quad Enhance, L-PARA, Dual-Combo L1 and L2

Shop Optolong filters at Adriasky with fast shipping to Italy and across Europe. Specialist technical support and official warranty on all products.