Optolong L2 Duo Combo - L-Synergy & L-eXtreme Duo Narrowband Filters - 2" - L2-DUAL-COMBO

This 2" imaging filter set includes both the Optolong L-Synergy SII/OIII 7nm Dual Narrowband Filter & the Optolong L-eXtreme Ha/OIII 7nm Dual Narrowband Filter.  

NGC 7000 in SHO ©RONALD BRECHER

The Optolong L-eXtreme is a dual-narrowband filter (OIII-7nm & Ha-7nm) designed to exclusively transmit the key nebula emission lines of OIII (500.7nm) and Hα (656.3nm). 

The L-Synergy is a dual-narrowband filter (OIII-7nm & SII-7nm) that guarantees high transmission for both the SII (672.4nm) and OIII (500.7nm) spectral lines.

By effectively blocking all other light pollution emission lines, both filters ensure that only the signals from their transmission lines are captured during imaging, achieving maximum effective transmission. With years of technological refinement, it significantly optimizes the performance in suppressing bright star halos.

The L2 Dual-Combo Set is engineered to unleash the power of Hubble Palette imaging for color camera users, supporting telescope systems as fast as F3.3 as well as slower systems.  Tailored specifically for color astro cameras, this innovative filter combination breaks through the traditional limitations of narrowband imaging with color cameras.

Without the need to switch to a monochrome camera or invest in an expensive SHO three-filter set, users can achieve stunning Hubble Palette images at a fraction of the cost and complexity.The core appeal of this combination design lies in lowering barriers and expanding possibilities for colour camera users: it preserves the equipment advantages of colour cameras while enabling users to unlock “Hubble-like” creative capabilities at minimal cost through minimalist filter combination.

Simultaneously, the L2 Dual Combo Set offers greater flexibility for astrophotography. Whether capturing nebular detail or reproducing deep-sky colours, this combination enables richer creative expression, truly unlocking the full potential of colour cameras in deep-sky photography.

Based on the characteristics of celestial emission lines and light pollution emission lines, the L2 Dual Combo Set preserves the distinctive colours of nebulae in OIII, Hα, and SII while filtering out the vast majority of light pollution. Specifically designed and optically optimized, its transmission profile is as follows: