Astronomik Oxygen 3 / O-III MaxFR 12nm High-Speed Imaging Filter - 36mm Round Unmounted
Ships by Next Business Day
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.
The Astronomik OIII filter is ideal for imaging nebulae showing oxygen emissions from both light-polluted and dark observation sites. It significantly enhances the contrast between objects emitting light at 496nm and 501nm (OIII lines) and the sky background. The Astronomik OIII filter completely filters out the emission lines from high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, as well as all lines of natural airglow and most of the distracting moonlight.
With a narrow bandwidth of either 12nm or 6nm and high transmission rates, the filter effectively blocks all unwanted light from wavelengths other than 496nm and 501nm from ultraviolet (UV) to infrared (IR).
Difference between Astronomik 12nm and 6nm filters
The choice between 12nm and 6nm Full-Width-Half-Maximum (FWHM) filters depends on your imaging conditions and camera type. There is no universal "best" option - each FWHM serves a specific purpose.
The 12nm Astronomik Narrowband-Emissionline filters are better suited for use with typical DSLR cameras with CMOS sensors and CCD cameras with normal or high dark current or if you are observing from suburban or dark-sky locations. They are also the preferred choice for cameras with an integrated or dual guiding sensor, as they generally show more guiding stars compared to the 6nm filter.
In areas with little light pollution, the background signal in images is usually limited by the sensor's dark current rather than light pollution. Therefore, further suppression of the sky background by reduction of the FWHM does not bring out more details in the object.
Difference between Astronomik MFR and MaxFR coating
Both the Astronomik MFR and MaxFR coatings give you the best out-of-band blocking over the entire wavelength range from UV to IR, extremely high contrast, minimized stray light, no halos and needle-sharp stars.
The MaxFR coating is designed to work perfectly with fast optical systems.
- For 12nm filters with MaxFR coating, this means unlimited usability from f/1.7 to f/8 and approximately 85% of the maximum transmission at a f/1.4.
Size of filter
Astronomik filters come in a wide range of standard sizes, both mounted and unmounted, to suit various optical setups and cameras.
This filter is a filter with a protective ring for filter wheels without screw thread. The glass thickness is 1mm, the mechanical thickness is 3mm, the diameter is 36mm.
Technical Data
- Guaranteed transmission of more than 90% (12nm) at the major OIII line (501nm)
- Typical transmission of 95% (12nm) at the major OIII line
- Glass thickness: 1mm
- Finely polished optical glass, free of any striae, residual stresses, and bubbles
- Extremely scratch-resistant and durable coating
- Completely resistant against high humidity and aging effects
- Astronomik MaxFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)
- Parfocal with other Astronomik filters
- Diffraction-limited
- Optimized spectral windows
- Delivered in a high-quality, long-lasting filter box
Additional Information
Due to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore effectively eliminated.
All Astronomik filters are ideal for modern cameras, including both CMOS- and CCD-based models, ensuring you capture the best possible images with your equipment. Sharpness, contrast, and the absence of any reflections and halos are guaranteed. Even with bright stars in the field of view, nebulae and galaxies will be captured with the finest structures.
Every Astronomik filter undergoes a rigorous quality control process before delivery. Additionally, each Astronomik Narrowband-Emissionline filter is measured using a high-end PerkinElmer Spectrophotometer to ensure it meets the specifications published on our website. On the back of each Narrowband-Emissionline filter box, you will find a label detailing the precise spectral data for that specific filter, including the maximum transmission and the recommended range of focal ratios.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
The Astronomik OIII filter is ideal for imaging nebulae showing oxygen emissions from both light-polluted and dark observation sites. It significantly enhances the contrast between objects emitting light at 496nm and 501nm (OIII lines) and the sky background. The Astronomik OIII filter completely filters out the emission lines from high- and low-pressure sodium (Na)- and mercury (Hg)-vapor lamps, as well as all lines of natural airglow and most of the distracting moonlight.
With a narrow bandwidth of either 12nm or 6nm and high transmission rates, the filter effectively blocks all unwanted light from wavelengths other than 496nm and 501nm from ultraviolet (UV) to infrared (IR).
Difference between Astronomik 12nm and 6nm filters
The choice between 12nm and 6nm Full-Width-Half-Maximum (FWHM) filters depends on your imaging conditions and camera type. There is no universal "best" option - each FWHM serves a specific purpose.
The 12nm Astronomik Narrowband-Emissionline filters are better suited for use with typical DSLR cameras with CMOS sensors and CCD cameras with normal or high dark current or if you are observing from suburban or dark-sky locations. They are also the preferred choice for cameras with an integrated or dual guiding sensor, as they generally show more guiding stars compared to the 6nm filter.
In areas with little light pollution, the background signal in images is usually limited by the sensor's dark current rather than light pollution. Therefore, further suppression of the sky background by reduction of the FWHM does not bring out more details in the object.
Difference between Astronomik MFR and MaxFR coating
Both the Astronomik MFR and MaxFR coatings give you the best out-of-band blocking over the entire wavelength range from UV to IR, extremely high contrast, minimized stray light, no halos and needle-sharp stars.
The MaxFR coating is designed to work perfectly with fast optical systems.
- For 12nm filters with MaxFR coating, this means unlimited usability from f/1.7 to f/8 and approximately 85% of the maximum transmission at a f/1.4.
Size of filter
Astronomik filters come in a wide range of standard sizes, both mounted and unmounted, to suit various optical setups and cameras.
This filter is a filter with a protective ring for filter wheels without screw thread. The glass thickness is 1mm, the mechanical thickness is 3mm, the diameter is 36mm.
Technical Data
- Guaranteed transmission of more than 90% (12nm) at the major OIII line (501nm)
- Typical transmission of 95% (12nm) at the major OIII line
- Glass thickness: 1mm
- Finely polished optical glass, free of any striae, residual stresses, and bubbles
- Extremely scratch-resistant and durable coating
- Completely resistant against high humidity and aging effects
- Astronomik MaxFR coating (Astronomik Deep-Sky RGB, UV-IR Block L-1, L-2, L-3, and Narrowband-Emissionline filters)
- Parfocal with other Astronomik filters
- Diffraction-limited
- Optimized spectral windows
- Delivered in a high-quality, long-lasting filter box
Additional Information
Due to the high-precision machining of the carrier substrate, all Astronomik filters are parfocal with wedge errors far below all common tolerances. Astronomik filters are diffraction-limited, ensuring that the optical performance (resolution and contrast) of your telescope is not compromised. Issues concerning focal distances and the exact alignment of images from each color channel are therefore effectively eliminated.
All Astronomik filters are ideal for modern cameras, including both CMOS- and CCD-based models, ensuring you capture the best possible images with your equipment. Sharpness, contrast, and the absence of any reflections and halos are guaranteed. Even with bright stars in the field of view, nebulae and galaxies will be captured with the finest structures.
Every Astronomik filter undergoes a rigorous quality control process before delivery. Additionally, each Astronomik Narrowband-Emissionline filter is measured using a high-end PerkinElmer Spectrophotometer to ensure it meets the specifications published on our website. On the back of each Narrowband-Emissionline filter box, you will find a label detailing the precise spectral data for that specific filter, including the maximum transmission and the recommended range of focal ratios.
| Free Shipping Graphic | Free US Shipping |
|---|---|
| Hide Found a better Shipped Price on Frontend? | No |
Astronomik Oxygen 3 / O-III MaxFR 12nm High-Speed Imaging Filter - 36mm Round Unmounted