More products from the brand :Antlia

Antlia Ultra Narrowband 2.5nm H-alpha filter

Price range: CHF 465 through CHF 590

Livraison contre signature gratuite
Easy, free returns

The Antlia H-a, SII and OIII 2.5nm Ultra filter series

Antlia SHO 2.5nm Ultra series filters are made of quartz glass and benefit from precisely controlled coating processes to guarantee optimum performance. Their half-value width (FWHM) is 2.5nm +0.3/-0.1nm, with a transmission efficiency of between 92% and 95% at the center wavelength.

The quartz glass used has a very low coefficient of thermal expansion, with excellent thermal and mechanical properties. Combined with advanced coatings, these filters offer outstanding durability, even under extreme environmental conditions.

Compared with the Pro 3nm series, the filters in the Ultra 2.5nm series provide better transmission of emission lines. The Hα line at 656.3nm reaches ≥95%, the SII lines at 671.6nm/673.1nm ≥95%, and the OIII line at 500.7nm ≥92%. These filters can improve the signal in your images by 20 to 30%. What's more, their narrow bandwidth offers an exceptional signal-to-noise ratio for deep-sky astrophotography.

Application and performance

Technical specifications

Hydrogen-alpha Sulfur-II Oxygen-III
Center wavelength (CWL) 656.3nm 671.6nm / 673.1nm 500.7nm
Maximum transmission ≥95% ≥95% ≥92%
Out-of-band discharge ≥OD5
Filter thickness 2mm ±0.05mm

Key features and applications

  • High transmission (Hα/SII ≥95%, OIII ≥92%) and narrow bandwidth to maximize contrast
  • Flat-top spectrum to limit losses due to CWL offsets
  • OD5 out-of-band rejection (0.001%) to avoid interference and halos
  • Made of quartz glass: excellent durability, scratch and break resistance
  • Standard thickness, double polished for perfect fit
  • Recommended for lenses with focal ratio ≥ f/3.5
  • Each filter is measured individually and accompanied by its actual transmission curves.
  • Edge-to-edge coating, black treatment on unmounted filters against internal reflections
  • 3-year warranty against delamination

Filter mounts

  • Standard Antlia ring: 1.25'' (M28.5*0.6), 2'' (M48*0.75)
  • Ultra-thin cell for reduced vignetting
  • Black anodized finish, unalterable laser engraving

Not recommended for :

  • Solar observation
  • Visual observation at night

Warning:

NEVER LOOK AT THE SUN WITH THESE FILTERS - This could result in serious eye damage.

Products in the same category

Filtre SII Antlia Ultra Narrowband 2.5nm
SII Antlia Ultra Narrowband 2.5nm filter
Price range: CHF 465 through CHF 590
LRVB - 2" Monté
LRVB - 2" Mounted
CHF 1'899
Set de filtres Antlia ALP-T Dualband 3.5 nm SII&H-beta et 3 nm Ha&OIII (2")
Set of Antlia ALP-T Dualband 3.5 nm SII&H-beta and 3 nm Ha&OIII filters (2")
CHF 729
Filtre SII Antlia 3nm Pro Highspeed
SII Antlia 3nm Pro Highspeed filter
Price range: CHF 279 through CHF 529
Filtre anti-pollution lumineuse MSM – Verre didyme pour la photographie nocturne
Filtre anti-pollution lumineuse MSM – Verre didyme pour la photographie nocturne
CHF 79
Filtre Dual Band pour Vespera
Dual Band filter for Vespera
CHF 379
Filtres photométriques Antlia SLOAN (g'r'i'z') - 4 pièces
Photometric filters Antlia SLOAN (g'r'i'z') - 4 pieces
CHF 1'439
Filtre Antlia ALP-T Dualband 3nm Ha et OIII
Antlia ALP-T Dualband 3nm Ha and OIII filter
CHF 349
Filtre Antlia ALP-T Dualband 5nm Ha et OIII Highspeed
Antlia ALP-T Dualband 5nm Ha and OIII Highspeed filter
Price range: CHF 319 through CHF 399
Colour Magic 2" Duo-band C Package(C1+C2)
Colour Magic 2" Duo-band C Package(C1+C2)
CHF 199
Filtre SII Antlia 3nm Pro
Antlia 3nm Pro SII filter
Price range: CHF 289 through CHF 759
Filtre OIII Antlia 3nm Pro
Antlia 3nm Pro OIII filter
Price range: CHF 289 through CHF 759
Filtre photométrique Chroma Sloan g' - 2" Monté
Chroma Sloan g' photometric filter - 2" Mounted
CHF 699
Filtre H-Beta Antlia 3nm Pro - 2"
H-Beta Antlia 3nm Pro - 2" filter
Filtre Chroma H-beta 5nm - 2" Monté
Chroma H-beta 5nm filter - 2" mounted
CHF 989
Filtre OIII Antlia 4.5nm Edge
Antlia 4.5nm Edge OIII filter
Price range: CHF 199 through CHF 359

Our new products

Celestron NexStar 8SE
Celestron NexStar 8SE
CHF 1'799
Dwarf Mini - En précommande
Dwarf Mini - En précommande
Price range: CHF 309 through CHF 439
Filtre anti-pollution lumineuse MSM – Verre didyme pour la photographie nocturne
Filtre anti-pollution lumineuse MSM – Verre didyme pour la photographie nocturne
CHF 79
Filtre MSM Easy Focus - Star Focus - idéal pour la photographie d'étoiles
Filtre MSM Easy Focus - Star Focus - idéal pour la photographie d'étoiles
CHF 59
Base de nivellement MSM à réglage fin ±5°, tête de trépied, base pour appareil photo avec vis 3/8"
Base de nivellement MSM à réglage fin ±5°, tête de trépied, base pour appareil photo avec vis 3/8"
CHF 45
Lampe frontale double éclairage pour photographie nocturne
Lampe frontale double éclairage pour photographie nocturne
CHF 25
Bande chauffante pour objectif / anti-buée pour astrophotographie (avec contrôleur)
Bande chauffante pour objectif / anti-buée pour astrophotographie (avec contrôleur)
CHF 29
Adaptateur baader 1.25" vers T2
Adaptateur baader 1.25" vers T2
CHF 29
WandererBox Pro V3
WandererBox Pro V3
CHF 379
Caméra planétaire Player One Mars-C II (IMX662 couleur)
Player One Mars-C II planetary camera (IMX662 color)
Original price was: CHF 199.Current price is: CHF 149.
[category_menu_mobile]