Astronomik H-alpha 12nm CCD Clip-Filter Nikon XL

Astronomik H-alpha 12nm CCD Clip-Filter Nikon XL

The Astronomik H-alpha filter is perfect for imaging hydrogen nebulae whether there is light pollution or not. You’ll see a clear contrast between the background and an object glowing at 656nm. Once you see it, you’ll wonder how you did without one of these!

This contrast boost is enabled by the high transmission of 96% of its 6nm narrow bandwidth, blocking all other unwanted bandwidths, and if you wanted a very dark background—this is how you get it.

The FWHM of 12 nm is optimized for typical DSLR cameras with CMOS sensors and CCD cameras with a normal/high dark current. With these cameras, the background signal in images taken from heavily light polluted sites is dominated by the dark current of the sensor. In this case, a further reduction of FWHM does not improve the image, as the background will not get darker. Compared to 6 nm filters this will yield more stars in the field of view which gives you more guiding stars when working with an integrated/dual guiding chip!

Thanks to the MFR coating technique, you may also use one single filter on all instruments up to f/3 without a significant reduction in performance.

DO NOT USE THIS FILTER FOR SOLAR OBSERVATION!

Technical data of the filter:

• Guaranteed transmission of more than 90% at the H-alpha Line (656 nm)
• Typical Transmission of 95% at the H-alpha Line (656 nm)
• Full-Width-Half-Maximum (FWHM): 12 nm
• Perfect blocking of unwanted light from UV up to the IR
• Parfocal with all Astronomik filters
• MFR Coating technique makes it usable with all optics up to f/3
• Thickness of 1mm
• Resistant to moisture, scratching, and aging
• An optically polished substrate, Striae-free, and free of residual stresses
• High-quality storage box