A. About Optolong's Moon and Skyglow FIlter
Optolong's Moon & Skyglow filter is designed to darken the background sky by blocking light transmission from skyglow (589nm) and many street light emissions from artificial light. Its high efficiency preserves image brightness, reveals more details and increases contrast of moon, galaxies, nebulae and globular star clusters.
B. Main Uses and Performance
- This is a versatile filter for visual observation and astrophotography of planetary nebulae.
- Enhance contrast of moon, galaxies, nebulae and globular star clusters.
C. Spectral Curve Transmission Characteristics
- Also blocks out infrared wavelengths (700-1100nm) so a separate IR cut-off filter is not required for imaging applications.
D. Technical Specifications
- Both surfaces are fine optically polished, accurate to 1/4 wavelength or better, and parallel to within 30 seconds or arc.
- 2mm thick Schott B270 optical glass substrate material.
- Very high surface quality of 60/40 or better (US Military Spec MIL-O-13830).
E. 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.
- Every single filter is tested and passed by Optolong before shipping to dealers.
- 1.25" astronomy filter with standard M28.5x0.6 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.
Jun 29, 2019
awesomePros: Cons: Comments:
From the moment we got it and looked out the window It was obvious how it would clear the haze and light pollution. It would be nice if they included a spectral graph. It does appear to be doing all the right frequencies.
This review was provided courtesy of AgenaAstro.comJun 13, 2019
Contrast improvementPros: Cons: Comments:
This filter is working well for me viewing with my Meade doublet refractor. The light polluted sky around bright objects is noticeably darkened using this. There is a slight purple glow on bright targets at times. Careful focusing seems to diminish the effect however.
This review was provided courtesy of AgenaAstro.comJan 16, 2017
Optolong Moon & Skyglow Light Pollution Reduction Filter - 2"Pros: Cons: Comments:
The filter works as advertised for skyglow and IR blocking.. However there is a raised ridge of chrome on the edge of the filter carrier housing that makes it slightly Larger than 2" and it is difficult to force the filter into a 2" adapter. If a tight adapter is used it will likely NOT fit into all holders and may therefore be unuseable. Lack of front threads to adapt for stackimng is already detailed.
This review was provided courtesy of AgenaAstro.comSort by