Optolong SHO 36 mm 6.5–7 nm Three-Filter Set (Optolong, SKU: SHO-36) includes unmounted H-alpha, OIII, and SII narrowband filters designed for imaging emission objects with monochrome cameras. The individual filters isolate the principal emission lines of hydrogen, oxygen, and sulfur, increasing the contrast of recorded structures against the sky background. The set enables data acquisition in three narrowband channels and the creation of images in the SHO palette, also known as the Hubble Palette.
• complete set of three H-alpha, OIII, and SII narrowband filters
• possibility of recording the three principal channels used in SHO astrophotography
• H-alpha filter with a 7 nm bandwidth centered around a wavelength of 656 nm
• OIII filter with a 6.5 nm bandwidth centered around a wavelength of 500 nm
• SII filter with a 6.5 nm bandwidth centered around a wavelength of 672 nm
• unmounted 36 mm format designed for compatible filter wheels
• construction intended primarily for use with monochrome astronomy cameras
• possibility of creating SHO palette compositions in which the SII channel is assigned to red, H-alpha to green, and OIII to blue
• increased contrast between an emission nebula and the sky background by limiting the transmission of light outside the selected band
• possibility of recording faint structures in emission nebulae, planetary nebulae, and supernova remnants
• reduction of the influence of some artificial lighting, including mercury-vapor and sodium-vapor emissions
• possibility of narrowband imaging in the presence of moonlight and from light-polluted locations
• multilayer anti-reflection coatings reducing unwanted light reflections
• precision coatings applied using ion-assisted deposition technology for increased durability and scratch resistance
• coating technology providing central wavelength stability during temperature changes
• planetary rotation system used during coating application to achieve high coating uniformity
• possibility of combining narrowband data with LRGB material to enhance nebular structures
• Optolong H-alpha 36 mm 7 nm unmounted filter – 1 pc.
• Optolong OIII 36 mm 6.5 nm unmounted filter – 1 pc.
• Optolong SII 36 mm 6.5 nm unmounted filter – 1 pc.
• manufacturer: Optolong
• set designation: SHO-36
• number of filters: 3
• filter type: astronomical narrowband filters
• filter format: unmounted
• filter diameter: 36 mm
• filter thickness: 2 mm
• set channels: H-alpha, OIII, and SII
• H-alpha filter central wavelength: 656 nm
• H-alpha filter bandwidth: 7 nm
• OIII filter central wavelength: 500 nm
• OIII filter bandwidth: 6.5 nm
• recorded OIII emission lines: 495.9 nm and 500.7 nm
• SII filter central wavelength: 672 nm
• SII filter bandwidth: 6.5 nm
• coating technology: multilayer anti-reflection coatings applied using ion-assisted deposition
• coating application method: planetary rotation system ensuring coating uniformity
• recommended application: narrowband astrophotography of emission nebulae, planetary nebulae, and supernova remnants
• recommended configuration: monochrome astronomy camera and a filter wheel supporting unmounted 36 mm filters with a thickness of 2 mm
• data processing method: separate acquisition of H-alpha, OIII, and SII channels followed by their combination in the selected color palette
• operating information: the filters increase the contrast of emission objects against the background but do not increase their actual brightness or completely eliminate the effects of light pollution
The complete set of H-alpha, OIII, and SII channels makes it possible to record extensive narrowband data and reveal structures in nebulae that are more difficult to capture through conventional broadband astrophotography.
