Optolong believes that the design of our L-eNhance filter is a technical innovation between filters. Effectively isolates the emission lines of H-Alpha, H-Beta and Oxygen III nebula and reaches a maximum transmission of up to 90%. The performance of this filter provides images that control the impact of polluted light skies.
L-eNhance Filter Spectrum Curve Based on the characteristics of the light body emission lines and the characteristic of light pollution of the spectrum, Optolong has specially designed and optimized the L-eNhance dual-band filter to maintain the predominant color of the RGB nebula while blocking most of light pollution. Spectrum as shown in the picture

Substrate: B270
Thickness: 1.85mm
Tpeak: T> 90%
Lock range: 300-1000nm
Block depth: block the light pollution line > 99%
Surface quality: 60/40
Transmitted Wavefront RMS: / 4.
Parallelism (arcsec): 30spact from bright and polluted skies.