L-Para (L-Parallels) is a dual narrowband 10nm light pollution filter. The FWHM of L-Para is 10nm for OIII (500.7nm) and H-Alpha (656.3nm) respectively. The transmittance of nebulae emission lines at are both greater than 85% in system with focal ratios of F2 and above. It effectively filters out mercury lamp, sodium lamp, and LED light pollution emission lines. At the same time, it has excellent contrast and anti-halo characteristics, allowing you to capture detailed and vivid nebula
Coating Technology
·Multi-layers anti-reflection coating
·Non-cementing optical substrate coating
·Optolong filter adopts precision coating based on Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL(central wavelength) no deviation affected by temperature change.
·Planetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-band.