Antlia Solar Discover 5 Angstrom CaK calcium filter for solar photography

Antlia calcium filter for solar photography with 0.5 nm bandwidth

The filter enables photography of the solar surface in the calcium K line around 393.3 nm. Due to an extremely narrow bandwidth of only 5 angstroms, structures such as flares, granulation and bright prominences are imaged with high contrast. The filter is intended exclusively for photography.

The calcium filter is optimized for refractors with a focal ratio of f/7 and slower. The aim is to get the solar disk onto the sensor as full-frame as possible. In order to change the image scale and to achieve a more moderate focal ratio with faster refractors, optional Barlow lenses (accessories area) can be integrated, which were specially developed by Antlia for the calcium filter.

The filter can be connected directly up to a lens aperture of 100 mm. From 100 mm or if a flatfield apo with integrated corrector is used, we strongly recommend an energy protection filter. The filter prevents the sun´s heat radiation from entering the inside of the telescope. Even with smaller apertures, an energy protection filter (ERF) will show an improvement in the image because the inside of the telescope and the inside of the filter do not heat up. You can find suitable ERFs in the accessories section. Attention - ERFs with pre-filtering for H-alpha only are not suitable for calcium photography because short-wave light is not transmitted.

Results from our customers

Our customer Armin Niebling photographed the sun through this filter and sent us two images of the ?First Light?, which we are pleased to present here:

Overview picture, please click to enlarge


Detailed view, please click to enlarge



Stephane Langlois has also used the filter successfully:

Übersichtsbild, zum Vergrößern bitte anklicken



We congratulate on the successful shots and wish clear skies and calm air for further successes.