Skyglow Filter Optolong 2"

Skyglow Filter Optolong 2"

SKYGLOW Optolong filters are interference filters designed to enhance deep sky observation in moderate light pollution conditions. They are designed to darken the background sky by blocking skyglow light (589nm); likewise, they also block most wavelengths of artificial light that cause light pollution, mainly those produced by mercury or sodium vapor lamps. In contrast, their maximum transmission corresponds to the hydrogen alpha and beta wavelengths. The background of the polluted sky, generally milky, appears darker and the contrast increases significantly, especially in the case of diffuse nebulae, such as Orion or the Lagoon. The improvement is also noticeable in galaxies and star clusters and even increases the contrast of the Moon.

Although this is an extremely versatile filter, its ideal use is for visual observation and astrophotography of planetary nebulae

Technical Specifications

• Thickness: 2.0mm
• Surface quality: 60/40 (refer to MIL-O-13830)
• Optically polished to ensure a precision λ /4 wavefront and parallelism of λ /4
• Multi-layer anti-reflective coating
• Non-cementitious optical substrate coating
• Its outermost coating with ion-assisted electron beam evaporation deposition technology gives it enhanced durability and scratch resistance, as well as CWL (center wavelength) stability unaffected by temperature changes.
• The planetary rotation system provides precision and homogeneity of coatings, ensuring high value in through-band transmission and out-of-band optical density
• The aluminum cell is manufactured by CNC machines requiring extreme manufacturing precision. The cell is of high fineness, the total aperture is 45 mm for the 2" (50.8 mm) size.

Skyglow Filter Optolong 2"