Name: Baader Planetarium 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted
Brand: Baader Planetarium
SKU: AAFIIIHSRD31
Price: 197.00 USD
Availability: BackOrder
Rating: 5 (1 reviews)

Baader Planetarium 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted

Baader Planetarium Filter

Baader Planetarium

Generally ships in 7-14 days, subject to availability

Special Order

Generally ships in 7-14 days, subject to availability Estimated to Ship: 07/24/2025.

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Adorama

Optics & Binoculars

Telescopes & Astronomy

Telescope Filters

Baader Planetarium Telescope Filters

Baader Planetarium Filter 

Shop the Baader Planetarium 31mm Oxygen-III Nebula Filter for maximum contrast with fast astrographs. High transmission, unmounted. Order today!

A 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted, is a specialized narrowband filter, meticulously engineered to meet the intricate needs of ultra-fast astrograph optics, specifically Hyperstar and RASA. Traditional narrowband filters often suffer from significant transmission loss due to a pronounced CWL-shift. In severe instances, the CWL may even shift out of the FWHM (CWL= Center-wavelength / FWHM= full width half maximum). To counteract this, our filters feature a CWL-preshift that perfectly aligns with f/2 to f/3 optics. The FWHM of this high-speed Oxygen-III Nebula Filter is expertly optimized. Despite the common line broadening associated with fast optical trains, this filter is capable of delivering maximum contrast, making it an essential tool for astrophotography. For the first time, these filters enable effective use of fast optics for high contrast emission nebulae imaging. When used between f/1.8 and f/3.5, these filters demonstrate a significant improvement over standard sets of narrowband filters. This 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted, is a game-changer for astrophotographers seeking to capture the breathtaking beauty of the cosmos with unparalleled clarity and contrast.

AstroSolar film is the standard for white light solar filters. This mounting cell has two great advantages for eclipse photographers. 

The wide flange shades your camera avoiding overheating. 

The external 3 rubber bumper attachment is easy to remove and replace quickly without disturbing your aim. This is a great advantage for totality in a total solar eclipse. 

Highly recommended

Baader Planetarium 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted

Key Features

Protect your gear with Adorama Protect.* Learn more

Baader Planetarium 31mm Round f/2 High-speed Oxygen-III Nebula Filter, Unmounted

Save 5% Every Day†

Key Features

Protect your gear with Adorama Protect.* Learn more

Save 5% Every Day^†