Astronomik H-alpha 12nm MaxFR XT Clip-Filter
The Astronomik H-alpha filter is ideal for imaging hydrogen nebulae. It works from both light-polluted and dark sites. It enhances contrast between objects at 656nm and the sky background. This h alpha filter blocks sodium and mercury lamp emissions. It also removes natural airglow and most moonlight. Note: this is not a hydrogen alpha solar filter — never use it for solar observation.
With a bandwidth of 12nm or 6nm, the filter blocks unwanted light. It covers wavelengths from UV to IR, outside 656nm.
The Astronomik H-alpha filter MUST NOT BE USED for solar observation!
Imaging with Astronomik Narrowband-Emissionline filters
The Astronomik H-alpha filter is the best first step in narrowband astrophotography. It lets you shoot deep, contrasty images under heavy light pollution or a full moon. It is ideal for red-glowing nebulae. Astronomik OIII filters add greenish and blueish structures. Astronomik SII filter completes the HSO palette for false-color imaging.
Difference between Astronomik H-alpha 12nm and 6nm filters
The 6nm filters suit star-crowded regions. They halve the number of stars in the image. They are ideal for very low dark current cameras or extreme light pollution.
The 12nm filters suit typical DSLR and CCD cameras. They also work well with cameras that have integrated guiding sensors.
Difference between Astronomik MFR and MaxFR coating
Both coatings give excellent UV-to-IR blocking, high contrast, and sharp stars.
- 12nm MFR-coated filters work from f/3 to f/∞.
- 6nm MFR-coated filters work from f/4 to f/∞.
The MaxFR coating is designed to work perfectly with fast optical systems.
- For 12nm MaxFR filters: unlimited use from f/1.7 to f/6. About 85% transmission at f/1.4.
- For 6nm MaxFR filters: unlimited use from f/2.2 to f/6. About 90% transmission at f/2.
- Filters for even faster optics are available on request.
Difference between Astronomik standard and XT Clip-Filters
The Astronomik XT-Filters are designed for wide-angle astrophotography. Standard Clip-Filters can stretch stars in image corners. XT-Filters use a 0.3mm or 0.5mm substrate to reduce aberrations. They maintain the same high optical quality and durable coating. More information about our XT-Filters can be found here.
Technical Specifications
- Guaranteed transmission >90% at the H-alpha line (656nm)
- Typical transmission: 96% (12nm), 93% (6nm)
- Glass thickness: 1mm (except OWB Type 3 and XT filters)
- Finely polished optical glass, free of striae, stresses, and bubbles
- Scratch-resistant and durable coating
- Resistant to humidity and aging
- Parfocal with other Astronomik filters
- Diffraction-limited
- Delivered in a high-quality filter box
Every filter passes rigorous quality control. Each unit is measured with a PerkinElmer Spectrophotometer. Spectral data is printed on each filter box label.
