Optolong OIII 6.5nm Narrowband Filter 36mm Unmounted (OPT-OIII-65NM-36MM) Manual Mount such as at dawn or

such as at dawn or dusk

Easy to use in the field

67° Linear Field of View (@1000 yds): 88 ft (27 m) Optical Coatings: StarBright XLT Optical Tube Length: 673mm (26

Housed in a 2" barrel like the 35mm

2") Secondary Mirror Obstruction by Diameter: 28% Secondary Mirror Obstruction by Area: 7

Optolong OIII 6.5nm Narrowband Filter 36mm Unmounted (OPT-OIII-65NM-36MM) Manual Mount such as at dawn orOptolong improved extra Narrowband OIII CCD 6. 5nm filter is designed for nebula observation allowing 6. 5nm bandwidth of light centered on a wavelength of 500nm through, which corresponds to OIII emission lines, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapour, and both high and low pressure sodium vapour lights and the unwanted natural light caused by neutral