Astronomik SII CCD Clip Filter for Canon EOS APS-C ONLY FOR DSLR no Mirrorless

The Astronomik SII-CCD filter is designed for CCD imaging of nebulae. Thanks to the narrow bandwidth of the SII, this filter provides a huge increase in contrast even under light-polluted skies. The 13nm bandwidth allows for transmission of up to 97%, a value impossible to achieve with narrower bandwidths.

With supernova remnants or planetary nebulae, Astronomik O-III filters make the difference between recording the object or not. The filter blocks all unwanted light, especially emission from mercury or sodium lamps from artificial lighting and the IR regions where CCDs are often very sensitive.

The optimal focal ratio for using these filters is between f/3.5 and f/6, but it can be applied to telescopes from f/2.8 to f/15. Unlike other narrower-band filters, the transmission loss of Astronomik filters only emerges if focal ratios lower than f/2 are used. Furthermore, it is possible to photograph objects across the entire field of view with maximum performance. This also makes it possible to use the external guiding sensor of cameras such as SBIG, which otherwise would not receive light with other types of filters.

Together with the H-alpha and OIII-CCD filters, you can now take three-color images even from particularly polluted skies.

In addition, thanks to the very high optical quality of these filters, the pinpoint sharpness of the stars is not diminished by the introduction of the filter.

Main features

Astronomik quality for a reliable and fulfilling observation experience.

• Filter diameter: Clip-in

Main technical specifications