Optolong L-Ultimate 2" Light Pollution Dual Band Filter

The Optolong L-Ultimate is an ultra-narrow 2" dual-band filter designed for astrophotographers looking to conquer heavy light pollution. Engineered for use with one-shot color (OSC) cameras, this filter allows only 3nm bandwidths centered at Hydrogen Alpha (656.3 nm) and Oxygen III (500.7 nm), resulting in spectacularly high contrast images.

By aggressively blocking all other light wavelengths—including street lamps, skyglow, and unwanted emissions—the L-Ultimate filter isolates critical nebulae emission lines, revealing deep-space targets in vivid clarity. With no halo effect around bright stars and superior signal-to-noise ratio, it's a top-tier solution for both amateur and advanced imagers alike.

• Filter Type: Dual-bandpass Light Pollution Filter
• Transmission Bands:
  • Hydrogen Alpha: 656.3 nm (3nm bandwidth)
  • Oxygen III: 500.7 nm (3nm bandwidth)
• Filter Size: 2" (50.8 mm) threaded
• Optical Thickness: 1.85 mm
• Filter Shape: Round
• Insert Style: Threaded – M48 x 0.75
• Compatibility: DSLR, CMOS, and CCD cameras (f/4 and above)
• Performance: Eliminates halos; ideal for nebulae imaging in light-polluted areas
• Warranty: Optolong – 2 Years

• Optolong L-Ultimate 2" Light Pollution Dual Band Filter
• Plastic Storage Case