Chroma 50mm OIII 3nm Telescope Filter

ITEM #
CF-OIII3-50
  • 50mm OIII 3nm Narrowband Filter
  • Parfocal for systems f/4.0 or slower
  • Transmitted wavefront better than 0.25 waves/inch
  • Made in America
  • Filter sizes up to 2-inch come with a complimentary TPO Filter Case (OS-CF2) to keep your filter safe.
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  • Regular price $750.00
  • $725.00
  • You save: $25.00 (3%)

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Chroma 50mm OIII 3nm Telescope Filter

Please Note: The interference coatings that optical filters are made with are angle-sensitive and shift to the blue with fast focal ratios. This is not a problem for filters 5nm or wider, but the 3nm filters shift enough to compromise transmission at the wavelength line of interest. Chroma has made a set of Ha, OIII and SII 3nm that are optimized for F/3 beams by moving the center wavelength slightly into the red so they will shift slightly to the blue when used in an F/3 beam, thus maximizing transmission at the nominal wavelength. For beams faster than F/3, we recommend using 5nm-wide or wider bands.

The Chroma 50mm OIII 3nm Narrowband Filter is essential for imaging objects, like nebulae, that are rich in ionized oxygen atoms. These line emission filters work extremely well in heavy light polluted areas and allow you image on nights when the moon is up.

Chroma manufactures the highest quality astronomy filters with durable, sputtered hard coating using single substrates of the best glass, eliminating the need for laminations. All primary filter coatings are applied on the front surface and anti-reflection coatings on the rear surface to prevent ghosting and to maximize transmission.

Highly precise and accurate, the passbands of these filters remain spectrally stable and do not drift in response to extreme temperature fluctuations or changes in humidity.

SPECIFICATIONS

Free ShippingYes
Bandpass3nm
Filter ShapeRound
Filter Thickness1mm
Filter TypeOIII
Free ShippingYes
Size50mm
Customer Reviews
5.0 Based on 1 Reviews
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Filter Reviews:
RG
08/08/2020
Raymond G.
United States United States
Chroma works for me

I have a full set of Chroma filters and they have worked well, with minimal reflections or star halos. The 3nm band width of the Ha and O3 really cuts down on the city light pollution sky background gradients.