or
07990646466
-
We are here to help
-
sales@widescreen-centre.co.uk
-
Monday to Saturday - 10:00am-4:00pm

Optolong H-beta 25nm Visual Nebulosity Filter

£68.00
(Inc. 20% VAT)
Loyalty Points: 68
Choose Filter Size
+
Product Code
OPT-HB25NM-1.25
Brand
Email us a question about this ProductOptolong
Description

Optolong H-beta 25nm Visual Nebulosity Filter

This premium Optolong Narrowband H-beta filter is designed for nebula observation allowing 25nm bandwidth of light centered on a wavelength of appr 490nm throughout, about halfway between the H-beta emission line and OIII. It also reduces 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 486.1nm and it is a blue colored filter. Some images of planetary nebulae and supernova remnants are taken with H-alpha, H-beta and OIII filters. They show great structural details, but have natural colors, looking like an RGB image.

Main Use and Performance

Suitable for visual observation on most emission nebulae, planetary nebulae and supernova remnants. Suitable for viewing on bright nebulae like M42 Orion Nebula in heavy light pollution. Use with a large aperture telescope under clear and dark viewing conditions with good seeing. Due to the fact that this filter will let through a larger amount of light around the OIII emission line, its main purpose is visual observations, however it can also be used with a small telescope for imaging deep sky objects.

Light pollution filters 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:

Optolong filters are not designed for solar observation. DO NOT LOOK AT THE SUN WITH ANY OPTOLONG FILTER as permanent eye damage will be the result.

Technical Data

  • Schott substrate material
  • Glass thickness 2.0 mm (1.25”/2”/36mm)
  • Surface Quality: 60/40 (Refer to MIL-O-13830)
  • Fine-optically polished to ensure accurate 1/4 wavefront and < 30 seconds parallelism over both surfaces
  • 90% transmission at major H-beta line 486.1nm, Partial transmission (appr 65-70%) of OIII line at 495.9nm.
  • Precision off-band blocking, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm).

Filter Cell

  • Ultra-thin filter cell minimise vignetting by maximising possible clear aperture (clear aperture is 26mm for 1.25” size and 45mm for 2” size)
  • Aerometal Material
  • Precise CNC Machining
  • Sand Blasting Process
  • Black Anodized Finish
  • Extinction Treatment to Prevent Reflection
  • Laser Engraving No Fading

Available Sizes

  • Standard 1.25” & 2”
  • Round 36mm Unmounted

Packaging

  • Plastic PP Case
  • Imported High Pressure EVA Case Lining
  • Silver Cardboard Box
  • High Density Sponge Carton Lining

Optical Coating

  • Multi-layer 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. (Please note, "planetary rotation system" is a type of optical coating process and does not refer to the astronomical system describing the motion of the planets in our solar system.)
Specifications

Specifications: Optolong H-beta 25nm Visual Nebulosity Filter

What's in the Box

What's in the Box: Optolong H-beta 25nm Visual Nebulosity Filter

  • Optolong H-beta 25nm Visual Nebulosity Filter
Downloads
Reviews (0)

Be the first to Write a Review for this item!

Delivery

At The Widescreen Centre, we prioritize prompt order processing and dispatch. We strive to dispatch all orders on the same day or the next working day, depending on the time of your order. We hold extensive stocks to ensure that your items are ready for immediate despatch. Please note that the cut-off time for same-day dispatch is usually 1:30 p.m.

For delivery within Mainland UK, we use reputable couriers to provide efficient service. You can expect your package to arrive in 1-2 working days. Please note that a signature may be required upon delivery to ensure a secure receipt.

In the case of special order items, the delivery time may be longer. If you have any concerns or questions about the delivery of your item, please don't hesitate to Contact Us. We are here to assist you.

Should there be any delay in dispatching your order, we will notify you to keep you informed.

Please be aware that The Widescreen Centre cannot be held responsible for any postal or third-party delays that may occur. We are committed to providing a reliable and efficient delivery service for our valued customers.

For more information please click here


FAQ - Have a question about this product? Fill in the form below and we will get back to you as soon as we can!

*
*
*
*
Please add the two numbers
Also Bought
Astronomik Dark Filter
Astronomik Dark Filter
From  £18.00
Astronomik UHC Filter
Astronomik UHC Filter
From  £89.00
Baader Hyperion Mark IV Universal Zoom 8-24mm Eyepiece
Baader Hyperion Mark IV Universal Zoom 8-24mm Eyepiece
£229.00
£237.00
OVL O-III Narrowband Filters
OVL O-III Narrowband Filters
From  £45.00
Teleskop Service Bahtinov Focusing Masks
Teleskop Service Bahtinov Focusing Masks
From  £20.00
ZWO 2" EFW 5/7-position Filter Wheel for 2" Filters
From  £318.00