1.25inch OPTOLONG CLS City Light Suppression Light Pollution Broadband Filter

Description

OPTOLONG 1.25" CLS City Light Suppression Light Pollution Broadband Filter Photography
Description:
The City Light Suppression broadband filter is designed to improve the visibility of various Deepsky objects. By selectively reducing the transmission of wavelengths of light pollutants, specifically those produced by artificial lightings including mercury vapor lamps, both high & low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). Together with the highly transparent in main nebula emission lines at OIII(496nm and 500nm), H-beta (486nm), NII(654nm and 658nm), H-alpha(656nm) as well as SII(672nm), the filter is suitable for enhancing the contrast and details for both visual and photographic purpose at sub-rural area.
Features:
Multi-layers anti-reflection coating
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) no deviation affected by temperature change.
Planetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-band.
Ultra-thin filter cell minimize vignetting by maximize possible
Aerometal Material Precise CNC Machining Sand Blasting
Process Black Anodized Finish Extinction Treatment to
Prevent Reflection Laser Engraving No Fading
95% transmission of main nebula emission lines (i.e. Ha 656nm, OIII 496nm&500nm, SII672nm and H-beta 486nm).
0.1% transmission of off-band, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nmand 578nm).
Suitable for color CCD cameras and unmodified DSLRs
CLS with wider pass-band than UHC and hence is more favored when observing under mild to moderate light pollution.
Light pollution filter do not eliminate the effects of light pollution or increase the object ' s brightness. In many cases, they increase the contrast between nebula and night sky, not brightening the nebula.
WARNING: The filters of OPTOLONG are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
Specifications:
Brand: OPTOLONG
Type: City Light Suppression Filter (CLS Filter)
Material: Optical glass lens, Aluminum Frame
Shape: Round
Thread: Standard M26.5*0.6mm
Net Weight: 3g / 0.12oz
Package Includes:
1.25" OPTOLONG CLS Telescope Filter