Optolong L-Pro (L-Professional) is a multi-bandpass filter which selectively suppresses the transmission of light pollution lines. For example, mercury vapor lamps, high and low pressure sodium vapor lights and skyglow caused by emission from neutral oxygen in our atmosphere. L-Pro enhances the transmission of major emissions from nebula while offering great colour balance with its wide yet effective light pollution cutting transmission band. The balanced transmission allows objects with wide emission spectrum such as galaxies to be imaged with minimal colour cast (easier to correct in post-processing). Among the emission lines enhanced are OIII (496, 500nm), H-beta (486nm), NII (654, 658nm), H-alpha (656nm) and SII (672nm).

• Multi-bandpass light pollution filter for astrophotography
• Clip filter design reduces internal reflection and colour cast shift
• Very high transmission (~90%) at major nebula emission lines
• Multi-layers anti-reflection coating
• CNC machined filter cell with aerospace grade aluminium and black anodised finish to extinguish reflections

Multi-bandpass light pollution filter for astrophotographyOptolong