Optolong Narrowband Ha Astroimaging Filter – 2 inch
Please note this is a 2 inch diameter round mounted astroimaging filter to fit directly to all standard CCD 2 inch Colour Filter Wheels which are commonly used globally by nearly every major CCD Manufacturer globally.
This is a premier quality filter from premier specialist astronomy & astroimaging filter manufacturer Optolong.
The H-alpha 7 nm Deep Sky Imaging Filter:
H-Alpha 7 nm filter is the most popular narrowband filter allowing 7 nm bandwidth of light centered on a wavelength of 656 nm through, 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 oxygen emission in our atmosphere (i.e. skyglow). Best choice of narrowband H-alpha astrophotography filter for highest contrast and revealing subtle nebula details.
Main Use and Performance
- Suitable for viewing on faint emission nebula of H-Alpha line in full moonlight or in severe light pollution
- Hubble look of images can be made by the combination of H-alpha, OIII-CCD and SII-CCD, such as the famous “Pillars of Creation” (M16 Eagle Nebula)
- Narrowband imaging with SHO set (H-alpha, OIII-CCD and SII-CCD) can be done with the moon up in heavy light pollution, so your equipment is not sitting dormant for several weeks
- H-alpha filter is the first narrowband addition to LRGB set for most imagers who blend a black-and-white Ha image into RGB data to enhance structural detail while maintaining natural look
- Narrowband 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.
Features of the Full Kit:
- Premier German Schott substrate material
- Thickness 2.0 mm
- 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 surfaces
- 95% transmission at bandpass with the LRGB filters
- The Ha filter has 80% transmission, the H-alpha line is 656 nm
- Infrared wavelength 700 to 1100 nm cut-off
- Precision off-band blocking
- 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 clear aperture
- Aerometal Material
- Precise CNC Machining
- Sand Blasting Process
- Black Anodized Finish
- Extinction Treatment to Prevent Reflection
- Laser Engraving No Fading