L-Pro is an abbreviation of L-Professional, light pollution restraint and high transmittance of nebulae emission lines are two points of this type. For the target object, the design of multi-bandpass with visible range 400-700nm, not rigidly natural flavor reinstated on subjective performance to express the feelings of colors, and reveal image details, which can be matched by no other experience. Because other light pollution filters type cut most of the details. In the light pollution environment, it is not only suitable for emission nebulae, reflection nebulae, but also for the objects with continuous spectrum so that make nebulae easier to see. Visually, L-Pro guarantee large amount of nebula emission through, and block certain types of artificial lights, which improving contrast efficiency of the object, not brightness... With CCD and DSLR is better choice for deep sky photography and wide-field astrophotography.