Elevate Your Astrophotography with Antlia Filters SII 2.5nm Ultra

Unlock the universe's brilliance with the Antlia SHO 2.5nm Ultra series filters, meticulously crafted from quartz glass and precision-coated to deliver unrivaled performance. Designed with a razor-thin FWHM (full width half maximum) of 2.5nm +0.3/-0.1nm and an exceptional transmission efficiency exceeding 93-95% at the Central Wavelength, these filters redefine deep sky imaging.

Quartz Glass Durability Our quartz glass filters boast an ultra-low thermal expansion coefficient, paired with remarkable thermal and mechanical properties. Coupled with advanced coating processes, they stand strong in the most challenging environmental conditions, making them ideal for cutting-edge imaging and research.

Enhanced Transmittance Compared to our 3nm Pro series, the 2.5nm Ultra series, coated on quartz glass, achieves even higher transmittance, with Ha/SII≥95% and OIII≥93%. Expect a significant 20-30% signal improvement in your images. The narrow FWHM of 2.5nm+0.3/-0.1nm elevates your Signal to Noise Ratio, perfect for capturing the depths of the cosmos in astounding detail.

Key Features:

• High transmittance (Ha/SII≥95%, OIII≥93%) and narrow FWHM 2.5nm +0.3/-0.1nm for maximum contrast.
• Flat-top spectrum minimizes transmission loss due to Center Wavelength (CWL)-shift.
• OD5 (0.001%) out of band blocking to eliminate interference and minimize halos around bright stars.
• Quartz glass construction for superior durability, thermal stability, fracture resistance, scratch resistance, and enhanced coating resilience.
• Identical filter thickness to existing standards with double-sided fine polishing and utmost care for parfocality.
• Recommended for optics with a Focus Ratio of ≥ f/3.5 for peak optical performance.
• Rigorous individual scanning ensures actual, measured spectra and transmission for every filter.
• Edge-to-edge coating and edge blackening for stray light elimination.
• Enjoy peace of mind with a 3-year warranty against delamination.

Please Note:

• Not recommended for solar imaging or night visual observation.
• DO NOT LOOK AT THE SUN WITH THIS FILTER; serious eye damage may result.

Elevate your astrophotography to new heights with the Antlia Filters SII 2.5nm Ultra series. Capture the cosmos with unrivaled precision and clarity.

Specifications

• FWHM (Full Width Half Maximum): 2.5nm +0.3/-0.1nm
• CWL (Central Wavelength): 656.3nm (H-alpha), 672.4nm (Sulfur-II), 500.7nm (Oxygen III)
• Peak Transmission: 95% for H-alpha and Sulfur-II, 93% for Oxygen III
• Blocking: ≥OD5 (Optical Density 5)
• Filter Thickness: 2mm+/-0.05mm
• Filter Ring Options: Available in 1.25’’ (M28.50.6) and 2’’(M480.75) Antlia standard ring sizes
• Optimized Design: Ultra-thin filter cell to minimize vignetting and maximize clear aperture
• Durable Finish: Black anodized finish for longevity
• Laser Engraving: Engraved markings for easy identification without fading