O-III Super-G Filter (9nm) - CMOS optimized

More Views

Images uploaded by Customers

Add Your Review with Images
O-III Super-G Filter (9nm) - CMOS optimized

Please choose product variant below to see price and SKU number

€ 89.00 Price excl. German VAT tax (19%): € 74.79

Please choose product variant below to see stock status  

  • O-III Super-G filter with 9 nm FWHM and a maximum transmission of 97%.
  • For visual and photographic observation of planetary nebulae and supernova remnants, even with small telescopes
  • Can be used as a "Super-G filter"  replacement for RGB photography. While regular G-filters suffer from bad seeing due to air turbulences, the narrow range of 9 nm passes less thermal noise, i.e. sharper images. Nevertheless, the transmission window is large enough not to be considered a pure narrowband filter.
  • CMOS-optimized coating technolog with much steeper slopes of the filter passband - for increased contrast, longer life and to avoid reflections.

* Required Fields

€ 89.00 Price excl. German VAT tax (19%): € 74.79

Product Questions and Answers

Do you have a question about this product? Then we would like to ask you to first look through the existing questions and answers, most likely your question has already been answered and you will get the desired information much faster this way. Your question is not listed? Then please click on the button "Ask a question".

Sort by ASC
What's the actual size of your 2" filters in "mm" with and without frame/ring? What step down adapter is suggested from a 52 mm to "-- mm"?
Question by: Waqas Ahmad on Oct 10, 2016 7:54:00 PM | 1 Answer(s)

Rating of Question

What are the threads and pitch of your 1.25" and 2" filters?
Question by: Anders G. on Sep 20, 2017 12:55:00 PM | 1 Answer(s)

Rating of Question

Please, what is the exact shape of the transmission band, is there any datasheet to download?
Actually I am searching for an OIII filter to cover both emission lines, 495.9 and 500.7 nm, as your 6.5 narrowband version covers only the 500.7 nm one. According to the whitepaper for narrowband filters, the transmission curve is shifted 2nm towards the red which prevents having both lines coverd in the 6.5 nm window....
Thank you for your answer, Petr.
Question by: Petr Cizek on Sep 4, 2023 11:57:00 PM | 1 Answer(s)

Rating of Question



Baader O-III Super-G Filter, 1¼" und 2"

The O-III filter is designed for observing and photographing those gas nebulae in which doubly ionised oxygen fluoresces - i.e. primarily for planetary nebulae and supernova remnants. With a FWHM of only 9 nm and equipped with the CMOS-optimised coating technology, it darkens the sky background and thus also blocks stray light much better than its 10 nm predecessor ( Baader O-III Filter (10nm) visual (various versions available) ). But the narrower FWHM is not the most important improvement. More important is the significantly better blocking aside of the O III wavelength, as well as even steeper transmission slopes and a broad plateau in the transmission range. With a transmission of 97% for the emission line at 500.7 nm, practically all the light of the nebula passes through the filter. At the same time, this filter can be used photographically for practically any focal ratio from f/1.8 to f/12 without passing any light of the H-beta line. This makes the Super-G filter just as ideal for use in areas with high light pollution.

Photographic use

The 9 nm O-III filter can be excellently used photographically on all telescopes, especially with a DSLR or an astronomical OSC colour camera. It offers all the advantages of the CMOS-optimised Baader filters such as Reflex-Blocker™ coating against reflections, plano-optical polishing and age-resistant Life-Coat™ coating. For monochrome cameras, we recommend the even stronger Narrowband (6,5 nm) and Ultra-Narrowband (4 nm) filters , which are available specially adapted for different aperture ratios. For this comparatively broadband 9 nm filter, preshifting is not necessary at focal ratios faster than f/4, thus it can be used at all focal ratios.

Super-G filter

The filter has the same thickness as the 1.25"/2" Baader LRGB filters. This makes it suitable for use as a "super G filter": In the transmission range of the normal green filter (490-580nm) there are no emission lines other than OIII; H-Beta at 486 nm is already covered by the RGB blue filter. So, when using the 9 nm O-III filter instead of the standard RGB green filter, emission nebulae are consequently emphasised much more strongly, while the stars appear fainter.

The Baader O-III Super-G filter has got all the advantages of the new generation of CMOS-optimized Baader filters:

  • Increased contrast, matched for typical CMOS quantum efficiency and s/n ratio
  • Reflex-Blocker coatings, for largest ever freedom from halos, even under most adverse conditions concerning aux-optics
  • Identical filter thickness to existing standards, with utmost care for parfocality
  • Blackened edges all around, with filter-lead-side-indicator in the form of a telescope-sided black outer rim, to additionally eliminate any reflection due to light falling onto the edge of a filter, making additional front-masks obselete
  • Each filter coated individually, with sealed coating edge (NOT cut out of a larger plate with coatings left exposed, read more)
  • Life-Coat™: evermore hard coatings to enable a non-aging coating for life – even in a most adverse environment

Baader Blogpost:
New CMOS-optimized Baader Filters

Related Articles

Additional Information

Technical Data not yet specifiedPlease choose product variant from dropdown above to see technical data of your chosen product

You may also be interested in the following product(s)

Overall Average Rating:
1 review
5 star
4 star
3 star
2 star
1 star
  • Date - Newest First
  • Date - Newest First
  • Date - Latest First
  • Highest Rated
  • Lowest Rated
  • Most Helpful

1 Item(s)

A.BRINGMANN 153/06/2023 03/06/202317:42
  • Rating:
O-III Super-G filter (9nm) - CMOS optimised - a new approach for urban RGB astrophotography
On the run from LED lamps and ever-increasing light pollution, I have tried to answer the following questions.
What happens if:
the new 20 nm H-alpha bandpass filter is used instead of a normal 100 nm R-filter and.
the new 9 nm O-III Super-G filter is used instead of the normal 100 nm G filter?

With the choice of the reflection nebula The Angel Nebula (NGC 2171) I have set the bar very high for the first test image. There are outstanding images of this object, e.g. from ChileScope, Lijiang Gemini Observatory or Namibia. At my location (Bortle scale 5), however, this faint nebula is a real challenge.

The result here is a "20 nm H-alpha / 9 nm Super-G / 100 nm B" image.
The new UHC-L / Ultra-L booster filter was used as luminance:

The Angel Nebula (NGC 2170) - a new approach to urban RGB astrophotography:

On the other hand, the new filters - 20 nm H-alpha bandpass filter and the 9 nm O-III Super-G filter - can be used as full line filters, as seen here:

Jellyfish Nebula (IC443 & IC 444) - testing new filters:

The EBV of this bicolour image was done according to the workflow of Marcel Drechsler:
Many thanks for your kind review! Since unfortunately it is not possible to render links in a product review, we have linked them again here below:
Show more comments (-5) Hide comments

1 Item(s)

What kind of abuse are you reporting?
    Please, wait...