H-Beta 12nm (Broadband Filter) 1.25”

Description

H-Beta 12nm (Broadband Filter) 1.25”
H-Beta 12nm (Broadband Filter) 1.25”
Broadband Filter H-Beta 12nm
Narrowband 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
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 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.
Technical Data
Schott substrate material
Thickness 2.0mm
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
90% transmission at H-beta line 486nm
0.1% transmission of off-band, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm). Transmission of 0.1% is equivalent to OD3(Optical Density), and a high optical density value indicates very low transmission, and low optical density indicates high transmission.
Coating Parameter
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
Filter Cell
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
Package
Plastic PP Case | Imported High Pressure EVA Case Lining | Silver Cardboard Box | High Density Sponge Carton Lining
Spectral Curve
The Major Emission Lines of Nebulae
H-β486.1nm OIII 495.9nm OIII 500.7nm H-α656.3nm
The Major Emission Lines of Artificial Light Pollution
Hg 435.8nm 546.1nm 577nm 578.1nm
Na 598nm 589.6nm 615.4nm 616.1nm
OPTOLONG astronomical filters launched since 1990s, OPTOLONG become China’s first astronomical filter manufacturers, with independent R&D ability, has successfully developed more than 20 popular astronomical filters so far.Since OPTOLONG astronomical filters launched, with its high cost performance and good after-sales service OPTOLONG astronomical filter received the recognition from customers and agents both at home and abroad.OPTOLONG astronomical filter has been cognition by fans all over the world, you are welcome to join our local agent.
OPTOLONG astronomy filters advantages
Optical performance: high precision wavelength, high transmittance, deep cutoff, good surface finish, no pinhole
Adopt precision optical double-sided polishing technology (< 30 “)
Halo is restrained effectively, good flatness (RMS λ / 4 or less)
Good substrate material, use German schott glass and fused silica glass
Aircraft aluminum ring by CNC machining, anodic oxidation treatment
Safety packaging, PP plastic box + PVC sponge + cartons
Shipping
Shipping cost:
We ship via United States Postal Service (USPS). The shipping calculations occur upon checkout.
Delivery time:
Most products ship within 2 business days.
Payment
We accept the following payment methods:
Paypal
We accept any major credit card, including American Express, Visa, MasterCard, and Discover, debit cards tied to a checking account, and prepaid cards
Please contact us if you have any questions.
Service
All of our products are new product and are shipped in good condition in packaging intended for them to arrive in good condition.  You can return any of our products within 90 days for any reasons and receive a full refund if the instructions have been followed. Included with the filter are instructions for use and care.
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