H-Beta for Visual Observation
H-beta filter is designed for nebula observation allowing 12nm bandwidth of light centered on a wavelength of 486nm through, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). H-beta emits 486nm and it is a blue-colored filter.
  • Description

  • Specification

1.Optolong H-Beta Introduction

 

H-beta filter is designed for nebula observation allowing 12nm bandwidth of light centered on a wavelength of 486nm through, and reducing the transmission of certain wavelengths of light, specifically those produced by artificial light including mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). H-beta emits 486nm and it is a blue-colored filter.

Main Use and Performance

Use with a large aperture telescope under clear and dark viewing conditions with good seeing.

Suitable for viewing on the faint and elusive Horsehead Nebula and California Nebula.

Use with a large aperture telescope under clear and dark viewing conditions with good seeing. 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.

WARNING: The filter of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER DIRECTLY. You would be BLIND if you fail to observe the warning.

 

2. H-Beta Spectrum for Reference

 

How to read the chart?

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

▲The vertical axis is transmission in %.

▲The WHITE line shows the transmission of the filter. The artifical emission lines are shown in ORANGE. And the emission lines from constellation are shown in GREEN.

 

 

3. H-Beta features

 

Specifications Applicable camera model Applicable lens Unit Price in US$
1.25" M28.5*0.5 / $90
2" M48*0.6 / $139

 

 

4. Manufacturing Technology

⭐High-precision grinding and polishing to make sure the substrate parallelism is greater than 30" and the surface accuracy is better than λ/4 ;

⭐Purified water ultrosonic clearning is aim to effectively remove impurities and dust from the substrate surface.

⭐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; IAD not only consolidates membrane compactness, increases film firmness, but also changes vacuum coating material characteristics.

⭐Planetary rotation system offers precision and homegeneity of coating ensuring high value on transmission of pass-band and Optical density of off-band;

⭐Non-cementing optical substrate coating;

⭐Quality Control: each filters is examined by Spectrophotometer for spectrum characteristic, and Laser Interferometer for surface accuracy.

 

 

 

5. Package 

 

2019 NEW package

※Note:We are now in the transition from the old to the new packaging style, ship is random.

 

 

 

 

6. Optolong H-Beta Performance

⭐H-Beta filter is suitable for visual observation. It should be observed with large diameter telescope. The small diameter telescope for observation will not be recommended.

⭐Suitable for observing the elusive Orion horsehead nebula and the California nebula, the horsehead nebula is clearly visible through the use of filters.

Optolong H-Beta filter features 1 type:

★1.25"(1 1/4" mounted), 2" mounted for eyepiece