The L-Pro (L-Professional) filter is best light pollution filter with multi-bandpass filter which offers better color balance by maximizing the transmission band. By selectively reducing the transmission of wavelengths of light pollutants, specifically those produced by artificial lightings including mercury vapor lamps, both high & low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). Together with the highly transparent in main nebula emission lines at OIII(496nm and 500nm), H-beta (486nm), NII(654nm and 658nm). It is suitable for enhancing the contrast and details for both visual and photograghic purpose at sub-rural area with heavy light pollution.
Check out Trevor's review of the L-Pro from Optolong