The Optolong L-Para is a dual narrowband filter that is also ideal for combating light pollution. The transmission range of the L-Para is 10 nm for OIII (500.7 nm) and H-Alpha (656.3 nm). The transmission of emission lines from nebulae is over 85% for optical systems with an aperture ratio of f/2 and above. The L-Para also effectively filters out the lines of mercury lamps, sodium vapour lamps and LED lights. At the same time, it has excellent contrast and anti-halo properties, allowing you to capture detailed and vivid nebula images.
The L-Para is suitable for both normal optics and fast optical systems such as RASA and Hyperstar. Even with oblique light incidence, it can achieve high transmission rates to give you clear and precise images.
Universal compatibility
A dual narrowband filter that is suitable for all telescope systems and can be adapted to fast optics (aperture ratios of f/2, f/2.8, f/3.2, f/4) as well as to various telescopes with 'normal' aperture ratios.
Strong against light pollution
The L-Para effectively blocks the emission lines of mercury lamps, sodium vapour lamps, LEDs and other sources of light pollution, making it equally suitable for skies rated 1-7 on the Bortle scale.
High transmission rate
In very fast optical systems with an aperture ratio of f/2 and higher, the transmission of the OIII and H-Alpha nebula emission lines is over 85%, resulting in higher image quality. Depending on the characteristics of the emission lines of celestial objects and light pollution, the L-Para can maintain high transmission in the OIII and H-Alpha spectrum.
