Dual Bandpass Light Pollution Reduction Imaging Filter W18982
Sale price
$38.99
Regular price $154.50
Skip to product information
A. About Optolong's L-e - Xtreme Filter - The Optolong 2” L-e - Xtreme filter builds on the success of the renowned L-e - Nhance filter to deliver an even higher degree of contrast when imaging emission nebulae, planetary nebulae, and supernovae remnants. The L-e - Xtreme is two filters in one. It has a narrow 7nm passband centered on H-alpha at 656nm and a second 7nm passband centered on OIII near 501nm. The majority of nebulae have their strongest emission at these two wavelengths. - Unlike the L-e - Nhance filter, the L-e - Xtreme blocks the weaker H-beta emission line at 486nm to deliver more contrast in the fainter regions of nebulae, even in light-polluted sky. The narrower passbands of the L-e - Xtreme are especially important in blocking moonlight and broadband light pollution found in many urban and suburban centers. - The L-e - Xtreme is an ideal filter for use with DSLRs, one-shot color (OSC), and monochrome CCD and CMOS cameras, especially with fast optical systems. It’s an indispensable filter for urban and suburban astrophotographers and for everyone who likes to extend their imaging sessions into nights when the moon is bright. - B. Spectral Curve Transmission Characteristics - FWHM: 7nm at O-III and 7nm at H-a - Blocking range: 300 - 1000nm - Light pollution line blocking depth: > 99%C. Technical Specifications - Both surfaces are fine optically polished, accurate to 1/4 wavelength or better, and parallel to within 30 seconds or arc.1.85mm thick Schott B270 optical glass substrate material. - Very high surface quality of 60/40 or better (US Military Spec MIL-O-13830). D. Optical Coating Specifications - Multi layer anti-reflection coated. - Non-cementing optical substrate coating. - Electron-beam gun evaporation with Ion-assisted deposition coating technology for durability and resistance to scratching, as well as stability on CWL (central wavelength) so that there is no deviation due to temperature changes during use. - Precise and homogeneous coatings ensure high values of desired passband and blocking of unwanted offband. - E. Other2 astronomy filter with standard M48x0.75 male filter thread (no female thread, so it cannot be stacked with other filters). Ultra-thin filter cell to minimize vignetting; clear optical aperture of 26mm. - Precision CNC-machined metal filter cell with sand blasted black anodized finish, anti-reflection treatment, and laser engraving. - High quality protective plastic storage case. - WARNING: Optolong filters are not designed for direct solar observation. NEVER use these filters for observing the Sun, or permanent eye and equipment damage will result. - F. Sample Images and Comparisons1. Compare L-e - Xtreme vs No Filter - Object: M42Date: 15-16 March 2020Location: Hong Kong - Shatin (Light pollution level 7~8, City center, light pollution disaster area - Camera: ZWO ASI183MC Pro - Telescope: Sky-Watcher N130/650 f/5 with coma corrector - Filter: Optolong L-e - Xtreme 2Mount: i - Optron CEM25ECGuide: 120mm mini guide scope, ZWO ASI120MM mini - Copyright: Vincent Cheng (Hong Kong)2. IC1396 (Elephant Trunk Nebula) to Sh2-129 (Flying Bat Nebula)The Optolong L-e - Xtreme is two 7nm filters
Dual Bandpass Light Pollution Reduction Imaging Filter W18982
Sale price
$38.99
Regular price $154.50
Shipping calculated at checkout.