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Model: O11802Brand: Optolong
Generally In Stock, Please Confirm Before Ordering
The Optolong CLS (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 photograghic purpose at sub-rural area.
Main Use and Performance
Suitable for color CCD cameras and unmodified DSLRsCLS with wider pass-band than UHC and hence is more favored when observing under mild to moderate light pollutionLight 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.
Schott substrate materialThickness 2.0 mm (1.25”/2”/36mm)Thickness 1.0 mm (Clip series)Surface Quality: 60/40 (Refer to MIL-O-13830)Fine-optically polished to ensure accurate 1/4 wavefront and <30 seconds parallelism over the both surfaces95% transmission of main nebula emission lines (i.e. H-alpha 656nm, OIII 496nm and 500nm, SII 672nm and H-beta 486nm0.1% transmission of off-band, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm). Transmission of 0.1% is equivalent to OD3(Optical Density), and a high optical density value indicates very low transmission, and low optical density indicates high transmission.Coating Parameter
Multi-layers anti-reflection coatingNon-cementing optical substrate coatingElectron-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 changePlanetary rotation system offers precision and homogeneity of coatings ensuring high value on transmission of pass-band and Optical density of off-bandFilter Cell
Ultra-thin filter cell minimize vignetting by maximize possible clear aperture (clear aperture is 26mm for 1.25”; 45mm for 2”)Aerometal Material | Precise CNC Machining | Sand Blasting Process | Black Anodized Finish | Extinction Treatment to Prevent Reflection | Laser Engraving No Fading
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Rother Valley Optics
Finance is now available on most products above £250! We offer 12, 24, 36 and 48 months with a fixed 15.9% typical APR. Please note this can't be done through the website at this moment in time. You will need to email us or drop into the shop to sort out finance. As long as the item is above £250, finance is generally available!
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Rother Valley Optics Ltd is registered in England and Wales 04762707. Registered Office: 21 Station Road, Kiveton Park, Rotherham, S26 6QP. Rother Valley Optics Ltd acts as a credit broker only. Rother Valley Optics Ltd are authorised and regulated by the Financial Conducts Authority. Credit provided subject to age and status..
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