Antlia 3nm Narrowband H-Alpha (Ha) Pro Imaging Filter - 2" Mounted

Our #: OFIL-AF-HA-2-Pro
Mfg #: HA-PRO-2
Our Price: $395.00
See shipping choices & costs

Your card isn't charged until your order ships

More info

Your credit card or Paypal account will not be charged when you place your pre/back order. However, your card issuer will place an 'authorization hold' (aka 'pending charge') on your card which reduces your credit limit. For Paypal, funds may be debited from your account based on your funding source. However, we will not charge your card or take the money from Paypal until the order is ready to ship.

Free shipping for this item in the US
More Info

Contiguous US Customers:
All items we sell ship for free within the Contiguous US. Shipping will be via the cheapest shipping method which will vary depending on the items in your order. During checkout, you may also be shown other optional faster shipping choices.

US Customers in Hawaii and Alaska:
Free shipping applies to almost all products. A few large telescopes and mounts are excluded from this free shipping offer. For these items, please contact us to obtain a shipping quote before you check out using the online shopping cart.

International Customers:
Free shipping does not apply to international orders. During check-out, you will be presented with several shipping choices and costs. However, the export of some items may be restricted outside the US due to size or manufacturer restrictions.

Back-order
Availability: Please contact us for an update

IMPORTANT: Please read this important note below before buying Antlia narrowband filters. No returns will be accepted for Antlia narrowband filters exhibiting halos around bright stars as disclosed below.

Please note that some users may see halos around bright stars in images made with this filter. Such halos have been observed with filters from other leading manufacturers and in the previous generation of Antlia narrowband filters as well. These halos can be caused and/or made worse by other optical accessories in the imaging train, their relative positions, telescope design/optics, camera, software, or a combination thereof. In general, OIII filters seem to have a higher propensity to show halos compared to H-alpha or S-II filters, but in rare cases the latter filters can also exhibit faint halos around bright stars.

Antlia has made great strides in their coatings to minimize haloing of bright stars, but you may still observe this effect to some degree. See the sample OIII image below of Alnitak (magnitude 1.74) and IC434 in Orion (SkyRover 155mm Apo, ZWO 6200MM-P Camera, 20 min exposure) provided by Antlia. In most cases, haloing will not affect your image unless you have very bright stars in the field of view. 

Antlia Filters OIII Halo

Please note we are unable to accept returns of any Antlia narrowband filters if you do observe this haloing effect in your images.

If you must ensure there are no detectable halos in your images, you may want to consider Astrodon or Chroma narrowband filters instead. These filters, however, cost two to three times as much as Antlia 3nm filters do. Antlia is being honest and upfront. They are the ones telling us about these halos, that their filters are great for the money but still not as good as Astrodon/Chroma, and pointing out that with this full disclosure, they will not accept returns. They are leaving it up to the customer to decide if this is good enough for them or not. We believe that for most imaging applications, Antlia filters continue to offer excellent value for astrophotographers and these continue to be among our top sellers.

Product Details

This H-alpha 3nm Pro narrowband filter is the upgraded version of the Antlia H-alpha 3.5nm filter. The narrower bandwidth of this filter enhances the contrast of nebulae that emit H-alpha by decreasing transmission of out-of-band wavelengths from light pollution, the moon, and chromatic aberration of bright stars. The filter rejects out-of-band wavelengths by up to 5 OD (99.999%).

This filter is suitable for imaging most emission nebulae, planetary nebulae and supernova remnants with monochrome astronomy cameras. It can bring out a tremendous amount of detail in nebulae where H-alpha emission is present. Because the filter passes little light outside the H-alpha band, longer exposure times and larger apertures or faster focal ratios may be necessary.

The H-Alpha 3nm Pro filter is designed to deliver >90% transmission at the center wavelength of 656.3nm. The transmission of the H-alpha 3nm Pro over its working bandwidth guarantees high transmittance when working with both long focal ratios and fast optical systems (as fast as f/3).

For the H-alpha 3nm Pro narrowband filter, we use latest coating technology to achieve 5 OD (0.001%) out of band blocking. Each filter is individually tested and scanned to ensure that product quality meets our high-performance parameters. The end result is a filter that achieves excellent contrast but with a price-to-performance ratio that compares more favorably than similar premium filters in the market.

Features:

  • Extra narrow 3nm bandwidth for superb contrast and ability to record the faintest H-alpha nebula detail
  • > 5 OD (0.001%) (out of band blocking) @300-1000nm
  • Steep spectral profile minimizes halos around bright stars
  • Peak transmittance guaranteed >90% at the emission line 656.3nm to increase the contrast in the shortest possible imaging time
  • 3nm Pro Narrowband filters are coated to the edge of the part and are edge blackened to minimize reflections and stray light
  • A single substrate to eliminate internal reflections
  • 3nm filters can be used with fast optical systems to f/3 with only slight loss of signal
  • Parfocal with Antlia LRGB, SII and OIII filters (telescope optics need additional consideration)
  • The Ha filter can be used with SII,OIII set of filters to achieve the impressive Hubble color palette
  • Superior optical reliability reduces post image processing
  • This filter is not suited to deep sky objects that do not contain Ha emissions
  • NOT SAFE FOR USE AS A SOLAR FILTER

Specifications:

  • Substrate: 2’’ mounted (2mm+/-0.05mm)
  • Surface Quality: 60/40 (Refer to MIL-O-13830)
  • 2 sides fine-optically polished to ensure accurate 1/4 wavefront
  • 30 arc second parallelism
  • Center-Wavelength of Antlia H-Alpha 3nm Pro filter: 656.3nm
  • H-Alpha 656.3nm T>90%, 90% transmission at H-Alpha line 656.3nm
  • > 5 OD(0.001%) @ 300-1000nm
  • 2 sides multi-layers anti-reflection coating
  • Single / Non-glued substrate

Filter Ring:

  • 2’’ (M48x0.75)
  • Ultra-thin filter cell to minimize vignetting
  • Black anodized finish
  • Laser engraving No fading

Not Recommended:

  • Visual observation
  • DO NOT LOOK AT THE SUN WITH ANTLIA FILTERS

Other Information

  • Country of Manufacture: China