Bresser EXPLORE SCIENTIFIC OPTOLONG 1.25 L-eNhance Deep-Sky Light Pollution Filter

L-eNhance Filter for Deep Sky Nebula Photography in Urban Environments

The increasing urbanization and associated light pollution pose significant challenges for amateur astrophotographers. The L-eNhance filter offers an economical and practical solution, enabling high-quality deep-sky nebula imaging even from light-polluted city locations. It is especially effective with affordable Newtonian telescopes, double-lens ED refractors, and achromatic telescopes.

Filter Characteristics

• Tri-band pass filter designed for DSLR, color CMOS, and monochrome CCD cameras.
• Isolates key nebula emission lines: H-Alpha (656 nm), H-Beta (486 nm), and Oxygen III (O-III, 496 nm & 500 nm).
• Maximum transmission up to 90% in the passbands.
• Effectively suppresses artificial light pollution from urban environments.
• Enables CMOS color cameras to achieve image quality comparable to monochrome CCD cameras.

Performance and Usage

The L-eNhance filter's narrow bandpass selectively transmits nebula emission lines while attenuating interfering light sources, allowing astrophotography without the need for large or expensive telescopes. It opens new possibilities for capturing high-class astronomical images directly from cities with heavy light pollution.

Warning: This filter is not designed for solar observation. Do not look at the sun through this filter to avoid permanent eye damage.

Coating Technology

The filter features multiple anti-reflective coatings applied via precision ion deposition technology. This ensures durability, scratch resistance, and stable central wavelength (CWL) unaffected by temperature changes. The coatings provide high transmission in the passband and strong optical density outside the passband, guaranteeing excellent image contrast and homogeneity.

Technical Features

• Professional photographic filter optimized for astronomy.
• Enhances deep sky emission nebula photography.
• Highly effective light pollution suppression.
• Suitable for imaging in heavily light-polluted areas.
• Tri-band filter with high transmission for O-III, H-Beta, and H-Alpha emission lines.
• Compatible with inexpensive Newtonian telescopes, double-lens ED refractors, and achromats.
• Enables CMOS color cameras to produce images comparable to monochrome CCD cameras.
• Balanced color output for natural image rendering.
• Filter diameter: 1.25 inch (31.7 mm).
• Connecting thread: M28.5 x 0.6 mm (standard 1.25 inch eyepiece thread).
• Selected high-quality optical glass material.
• Spectrum range: 300–1000 nm.
• Off-band blocking: >99%.
• Surface quality: 60/40 (per MIL-O-13830 standard).
• Fine optical polishing ensuring 1/4 wavefront accuracy and highest parallelism on both surfaces.
• High transmission at major nebula emission lines (H-alpha 656 nm, OIII 496 nm & 500 nm, H-beta 486 nm).

Scope of Delivery

• 1 x L-eNhance filter (1.25 inch diameter)
• 1 x Dust protection box