Optolong Filters L-eXtreme F2 (2") (80191)

The Optolong L-eXtreme filter is a dual 7nm bandpass filter designed for astrophotography with one-shot color cameras such as DSLRs, as well as with monochrome CCD cameras. It is particularly well-suited for fast optical systems and offers an affordable solution for amateur astronomers who want to capture rich images of emission nebulae, even under bright, light-polluted skies. By isolating the H-alpha and Oxygen III (OIII) emission lines, the filter maximizes contrast and signal-to-noise ratio, making it an excellent choice for imaging in areas with heavy light pollution or during times when the moon is visible.

A key advantage of the L-eXtreme filter is that it blocks all light between the H-beta and OIII lines, where there are no nebula emissions. This feature prevents unwanted light pollution from passing through, resulting in a darker sky background and stronger nebula signals in your images. The filter is specifically designed to isolate only the important emission lines, offering superior protection against light pollution compared to broader band filters.

Unlike the L-eNhance filter, which is a tri-band filter transmitting H-beta, H-alpha, and OIII, the L-eXtreme filter is a dual-band filter that transmits only H-alpha and OIII emission lines.

Specifications and Features

Coating of optical system: Multiple coatings for high performance and durability
Frame: 2-inch filter size
Mount material: Aluminium for lightweight strength
Transmission: 99% at the H-alpha and OIII emission lines
Surface accuracy: 4 (high optical quality)
Type: Ultra High Contrast (UHC) filter
Diameter: 2 inches
Photographic use: Yes
Anti light-pollution: Yes
Visually useful: No, designed for imaging only
Nebulae & galaxies: Yes
Planetary nebulae: Yes
Hydrogen nebulae: Yes
Supernova remains: Yes
Galaxies and star clusters: Not specified
H-alpha: Yes