Optolong Night Sky H-Alpha filter 2"

Optolong Night Sky H-Alpha Introduction

Night Sky H-Alpha filter (IR Pass 650nm) with 50% transition from blocking to passing at about 640nm and 95% or above transmission at wavelengths longer than 650nm can be used in IR-LRGB imaging to produce a sharper luminance image for the best planetary contrast as atmospheric seeing and distortion is much reduced at longer IR wavelengths.

Main Use

The sensor of CCD or CMOS cameras is capable of detecting light in the 350-1100nm range including infrared wavelengths. Thus RGB planetary images taken with IR as the luminance channel have visible-enhanced contrast and surface detail than standard LRGB images.

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.

Optolong Night Sky H-Alpha Spectrum and Characteristic
Sbustrate: Optical glass
Thickness: 1.85mm
Tave:  T>90%
Blocking range: 300-570nm
Surface quality: 60/40
Transmitted Wavefront RMS: λ/4
Parallelism: 30s

How to read the chart?

The horizontal axis is the Wavelength in Nanometers(nm).

The vertical axis is transmission in %.

The RED line shows the transmission of the Night Sky H-Alpha filter.

Coating Technology

·Multi-layers anti-reflection coating

·Non-cementing optical substrate coating

·Optolong filter adopts precision coating based on 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.