Optolong 2" L-Enhance Dual Narrowband Light Pollution Filter (H-Alpha and H-Beta/O-III)

The relentless spread of urbanization and its associated light pollution have become a growing problem for all amateurs and astro photographers. The current solutions to the problem can be expensive and might include the purchase of a monochrome camera, several types of narrowband filters and a filter wheel. L-eNhance provides an economical and practical solution for amateurs. It is a dual band-pass narrowband filter which has been designed for DSLR (digital SLR), color CMOS and CCD Astrophotography Cameras. The convenience and cost effectiveness of this filter allows amateurs to image a rich selection of astronomical images, even in bright, heavily light-polluted areas. Optolong believes the design of our L-eNhance filter is a technical innovation among filters. It effectively isolates the H-Alpha, H-Beta, and Oxygen III nebula emission lines and achieves a maximum transmission of up to 90%. The performance of this filter delivers images that superbly control the impact from light polluted skies. According to the characteristics of celestial body emission lines and the light pollution spectrum, Optolong specially designed and optimized dual-band L-eNhance filter in order to retain the prominent color of nebula RGB while blocking out most of light pollution. The Optolong L-eNhance filters have threads on one side - they can be used with filter wheels, filter drawers, focusers with a place to thread focal reducers internally (such as some Moonlite focusers) and camera nose pieces that fit into compression rings but the filter should not be threaded into the imaging train like an adapter ring with threads on both sides. Substrate: B270 Thickness: 1.85mm Tpeak: T>90% Blocking range: 300-1000nm Blocking depth: Light pollution line blocking >99% Surface quality: 60/40 Transmitted Wavefront RMS: λ/4 Parallelism (arcsec): 30s