Optolong L-eXtreme Filter 1.25 inch

Optolong Filters L-eXtreme 1.25″ is a high-quality narrowband filter designed specifically for astrophotography of emission nebulae with color cameras (OSC) and DSLRs. The filter allows only two major emission lines to pass through: H-alpha (656 nm) and OIII (500 nm). Interfering wavelengths from artificial light are almost completely blocked, making nebulae appear much more contrasty and bright in the photograph.

Thanks to its dual transmission, this filter is ideal for cameras with a Bayer pattern because both color channels are efficiently utilized. This makes the L-eXtreme filter particularly effective for nebulae such as the Veil Nebula, the Orion Nebula or the North American Nebula. The sky background is greatly darkened, enabling impressive results even in urban areas with significant light pollution.

Compared to wider filters such as the L-eNhance, the L-eXtreme offers even higher selectivity and contrast, which is especially useful for narrowband photography under heavy light pollution or during moonlight. The filter is constructed of high-quality optical glass with multiple anti-reflection coatings and mounted in a rugged 1.25″ aluminum mount.

Observation goals
This filter is ideal for astrophotographers who want to photograph emission nebulae with a color camera or DSLR, even from the city. Suitable for long exposure times and stacking. For visual use, this filter is less suitable because the extremely narrow bandwidth allows too little light to pass through for the human eye.

Specifications

• Type: Narrow-band filter (dual-band)
• Diameter: 1.25″ mount
• Transmittance: H-alpha (656 nm) and OIII (500 nm)
• Material: Optical glass with multiple coating
• Mount: Aluminum
• Application:
  • ✓ Astrophotography of emission nebulae
  • ✓ Suitable for OSC cameras and DSLRs
  • ✓ Works in light-polluted areas
  • ✗ Not intended for visual use