Astronomik OIII 6nm CCD MaxFR 1.25'' (M28.5) Filter for Astrophotography

MaxFR Narrowband Emission Line Filters for Fast Optical Systems

There is an ever-growing demand for astrophotography filters suitable for extremely fast optical systems like Celestron's RASA and Takahashi's Epsilon Astrographs. The Astronomik MaxFR series of narrowband-emission line filters is designed to deliver the highest quality data for fast optical systems, enabling deep-sky imaging with maximum contrast and minimal stray light.

Why Choose Astronomik MaxFR Filters for Astrophotography?

The MaxFR emission line filters are engineered to work with fast focal ratios, making them ideal for deep-sky imaging. You can select filters with 12nm or 6nm bandwidth (FWHM) for the three most important emission lines in astrophotography: oxygen (OIII), hydrogen (H-alpha), and sulfur (SII).

Key Features of Astronomik OIII 6nm CCD MaxFR Filter

• Highest transmission for excellent image quality.
• Minimized stray light and no halos.
• Needle-sharp stars in your astrophotography images.
• Compatible with fast optical systems, suitable for focal ratios as low as f/1.4.
• Durable coating, resistant to scratches and moisture.
• Available in 1.25" up to 50mm x 50mm filter sizes.
• 10-year guarantee on all Astronomik filters.

How Astronomik MaxFR Filters Improve Astrophotography

The new MaxFR filters are made with advanced MFR coating technology, providing exceptional out-of-band blocking across the entire wavelength range from UV to IR. This ensures an extremely high contrast, reduced stray light, and no halos in your final astrophotography images.

MaxFR Filter Performance at Different Focal Ratios

• 12nm Filters: Usable from f/1.7 to f/8, with about 85% of maximum transmission at f/1.4.
• 6nm Filters: Usable from f/2.2 to f/8, with about 90% of maximum transmission at f/2.

Narrowband Imaging with Astronomik Filters: Boost Contrast and Block Light Pollution

If you frequently image from light-polluted areas, narrowband-emission line filters are your best tool for capturing high-contrast deep-sky images. An H-alpha filter is often the first choice for imaging red nebulae, while OIII filters expand your imaging possibilities by revealing blue-green nebulae and planetary structures. Combine H-alpha, OIII, and SII filters to create stunning Hubble Space Telescope-like images.

FAQ: Which Bandwidth Should I Choose - 6nm or 12nm?

Choosing between 6nm and 12nm depends on your imaging setup and location. For cameras with low dark current and effective cooling, the 6nm filter is ideal for reducing background light and capturing fainter details. The 12nm filter is suitable for DSLR cameras and imaging setups with limited cooling or dark current control.

How Astronomik Filters Enhance Exposure Time

With Astronomik narrowband filters, you don’t have to increase exposure time, but you can if needed. The filters allow nearly all emission line photons to pass through while blocking unwanted light, giving you the flexibility to capture deeper images with longer exposures, especially in light-polluted areas.

Why Astronomik Filters Are the Best Choice for Astrophotography

• MFR Coating: Filters can be used down to f/1.4 for 12nm and f/2 for 6nm.
• High-Quality Substrate: Made from stress-free, optically polished glass for perfect images.
• Parfocal Filters: Astronomik filters are parfocal, so no refocusing is needed when changing filters.
• Durability: Resistant to scratches and moisture, with no performance degradation over time.
• Integrated Blocking: Blocks unwanted light from UV to IR, eliminating the need for additional UV/IR blocking filters.
• Wide Range of Sizes: Available in sizes from 1.25" to 50mm x 50mm square filters.
• 10-Year Guarantee: Astronomik offers a 10-year guarantee on all filters.