【IMPROVED】H-Alpha 7nm Narrowband Filter
H-Alpha 7nm filter is the popular narrowband filter allowing 7nm bandwidth of light centered on a wavelength of 656nm 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). Better choice of narrowband H-alpha astrophotography filter for highest contrast and re
  • Description

  • Specification

1. Optolong H-Alpha 7nm Narrowband Introduction

H-Alpha 7nm filter is the popular narrowband filter allowing 7nm bandwidth of light centered on a wavelength of 656nm 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). Better choice of narrowband H-alpha astrophotography filter for highest contrast and revealing subtle nebula details.

  • 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.

 

2. Referance Spectrum

How to read the chart?

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

▲The vertical axis is transmission in %.

▲The H-Alpha7nm line is shown in  RED

 

3. Improved Version of H-Alpha7nm Narrowband Filter 

 

Optolong H-Alpha7nm Filter Specifications Applicable Model Unit Price in US$
1.25" /1 1/4" mounted) M28.5*0.5 $175
2" mounted M48*0.6 $259
31mm unmounted CCD filter wheel $190
36mm unmounted CCD filter wheel $193

 

 

 

 

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. Packing

2019 NEW package

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

 

 

6. Filter Performance

I.NGC6888, by Andrea Andreotto Maggi Astrophoto

Camera Moravian CCD & CMOS cameras G2 8300
Telescope Sharpstar Optics107 Artesky
Filter Optolong Astronomy Filter H-Alpha7nm, OIII6.5nm
Mount Sky-Watcher Az eq6
Software APT - Astro Photography Tool PixInsight Photoshop
18 light 900 sec HA
18 Light 900 OII

 

 

II. Wide field from Rosette Nebula to Cone Nebula in Monoceros, imaged by José Jiménez.

Canon 6D + Star71 
Mosaic two panels
RGB 20 x 600" ISO 3200 Optolong L-eNhance filter
H-alpha 15 x900" ISO 3200 Optolong H-Alpha filter
OIII 15 x900" ISO 3200 Optolong OIII filter
SII 15 x900" ISO 3200 Optolong SII filter

La Jonquera & Albanyà ( IDAS - International Dark Sky Park )
Optolong Astronomy Filter

 

 

III.  Spiral Galaxy NGC 2403 by Terry Hancock 

NGC 2403 is a Spiral Galaxy in the constellation Camelopardalis, having a diameter of roughly 50,000 light years (similar in size to M33) and like M33 it has many magnificent star forming HII regions as can be seen in this photograph. NGC2403 lies at a distance of approximately 8 million light years from planet earth.
Captured using data from Grand Mesa Observatory’s system 3 the Planewave 12.5” CDK telescope and Warren Keller’s ATIK 11000 Mono CCD Camera
Captured over 2 nights in November and December 2019 for a total acquisition time of 15.5 hours. 
Technical Details
Captured and processed by: Terry Hancock
Location: GrandMesaObservatory.com Purdy Mesa, Colorado
November 1st and December 17th 2019
HA 290 min 19 x  600 sec
LUM 290 min 29 x 600 sec
RGB 30 x 300 sec x 3
Narrowband Filters by Optolong
Camera: ATIK 11000 (courtesy of Warren Keller)
Gain 2850, Offset 76 with Dark Frames no Flat.
Optics: Planewave 12.5” CDK F8, 2541mm focal length
Mount: Paramount ME
Image Acquisition software Maxim DL6
Pre Processing in Pixinsight
Post Processed in Photoshop CC


 

IV. Sharpless 2-240 (the Spaghetti Nebula), from Chuck's Astrophotography

Sharpless 2-240 (the Spaghetti Nebula) is a supernova remnant (SNR) in the Milky Way, straddling the border between the constellations Auriga and Taurus. It was discovered in 1952. It is estimated to be around 3,000 light years from earth and has an age of around 40,000 years.
This nebula is huge, it probably would have taken a mosaic of 9 to 12 panels to capture the whole thing. It's captured using narrowband filters, but I decided to go for a more natural look leave out SII. I put Ha in the Red Channel and OIII in the Green and Blue Channels.

Here are the specs:
Imaging Telescope: Orion ED80T CF
Mount: Sky-Watcher EQ6-R Pro
Imaging Camera: ZWO ASI1600MM Pro
Focuser:
MoonLite 2.5" Focuser with Motor Auto-Focus
Focal Reducer: Orion .8 Reducer
Polar Alignment: QHYCCD PoleMaster
Frames:
Optolong Ha: 159x240" (gain: 139, offset: 21)
Optolong OIII: 130x240" (gain: 75, offset: 15)

Integration: 19.27 hours
Guide Scope: ZWO 60mm Guide Scope
Guide Camera: ZWO ASI224MC
Guide Software: PHD2
Calibration Frames:
Darks: 50, Bias: 200, Flats: 50
Capture software:
Sequence Generator Pro (SGP)
Stacking software: PixInsight
Post Processing: PixInsight, PhotoShop
Dew Shield, Dew Heater Strip

 

V. The Veil Nebula, from Chuck's Astrophotography

The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus. The source supernova was a star 20 times more massive than the Sun, which exploded around 8,000 years ago. It's around 1,500 light years from Earth.
This the western segment of the Veil Nebula (NGC 6960), also known as the Witch's Broom. Below it is Pickering's Triangle. I put Ha in the Red Channel and OIII in the Green and Blue Channels. Here are the specs:
Imaging Telescope: Orion ED80T CF
Imaging Camera: ZWO ASI1600MM Pro

Focuser:
MoonLite 2.5" Focuser with Motor Auto-Focus
Focal Reducer: Orion .8 Reducer
Mount: Sky-Watcher EQ6-R Pro
Polar Alignment: QHYCCD PoleMaster

Frames:
Optolong Ha: 60x240" (gain: 139, offset: 21)
Optolong OIII: 60x240" (gain: 75, offset: 15)

Integration: 8.0 hours
Guide Scope: ZWO 60mm Guide Scope
Guide Camera: ZWO ASI224MC
Guide Software: PHD2
Calibration Frames:
Darks: 50, Bias: 200, Flats: 50
Capture software: 
Sequence Generator Pro (SGP)
Stacking software: PixInsight
Post Processing: PixInsight, PhotoShop
Dew Shield, Dew Heater Strip


 

VI. IC410 The Tadpoles & IC405 Flaming Nebula, shot by José Jiménez

IC 405 ( to the right in this image) is also known as the Flaming Star Nebula. It is both an emission (glow from ionized gas) and reflection (light reflected from dust) nebula. 
IC 410 is a beautiful and complex emission nebula about 12,000 light-years located in the sky just 1.5 degrees away from IC 405 The distinguishing feature of IC 410 are the two "tadpoles" at the lower, which are spectacular examples of star-forming

Canon 6D mod - TS Imaging Star71 - WO SpaceCat 51
RGB 25 x 600" ISO 3200 - Optolong L-eNhance filter
H-alpha 12 x900" ISO 3200 - Optolong H-Alpha filter
La Jonquera & Albanyà - Girona

 

 

Warm Reminder:

  • About Color: The package may different due to different photography environment, lighting. What you have seen in the picture is absolutely what it is being. You might feel somewhat of color different subject to the monitor and camera, please refer to the material item.
  • About Coating: The interference items will show rich colors in different light environment, which is normal phenomenon.
  • About Product Object: Product specifications may change to improve product quality, and that updates to the specifications will be published as soon as possible.
  • About Product Overview: Please note that H-Alpha 7nm filter with same design, same raw material . Size is the only difference

Optolong SHO6.5nm features 4 sizes:

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

★Round 31mm unmounted, 36mm unmounted for filter wheel