Antlia Solar Discover 5ÅCaK
The Antlia Solar Discover 5Å CaK is a specialized optical package for solar imaging, incorporating light reduction filters to limit solar heat gain and improve safety of use. Designed to maximize the contrast of Plages, Light Bridges and sunspots on the Calcium II K line (393.3nm), it offers an ultra-narrow bandwidth of 0.5nm to capture fine details of the solar chromosphere.

Key features
- Integrated filter: ultra-narrow bandwidth 5Å (0.5nm) centered on 393.3nm
- Clear aperture: D12mm (B1200)
- Fully enclosed tube in CNC aerospace aluminum, preventing light leakage
- Effective heat reduction for safe solar imaging
- Installation similar to the Herschel CaK 3nm prism
Compatibility and Accessories
- For use with telescopes with focal ratio > f/7 without Barlow
- Barlow 2X, 3X, and 5X for Solar Discover 5Å CaK (optional)
- Adjustable aperture diaphragm Dia 2.0mm-25mm (optional)
- Focal length extensions: 50mm and 70mm tubes available as options
- Secure installation required with additional ERF for optics > 100mm aperture
Important notes
- No additional light reduction device, limited to refractors up to 100mm aperture
- ERF required when using other brands of zenith or Barlow mirrors
- Correct installation essential for safe operation
Visual use
The CaK band (393.3nm) is almost invisible to the human eye. Solar Discover 5Å CaK is designed primarily for imaging and is not recommended for visual observation. Furthermore, the IR coverage of the filters does not correspond exactly to ISO 12312-2 standards. Any visual use should be carried out with extreme caution and only if the filters are in perfect condition.
Compliance with ISO standards
- Tmax% (380-780nm): 0.0032%
- Tmin% (380-780nm): 0.000061%
- Tmax% UVB (280-315nm): 0.0032%
- Tmax% UVA (315-380nm): 0.0032%
- Tmax% IR (780-1700nm): 3%
Solar Discover options (select from drop-down menu)
- Solar Discover 5Å CaK Assembly alone: USD 880
- Solar Discover 5Å CaK with Barlow 2X or 3X: 930 USD
- Solar Discover 5Å CaK with Barlow 5X: 940 USD
- Barlow 2X or 3X alone: USD 50
- Barlow 5X alone: USD 60
- Adjustable diaphragm: USD 50
- 50mm extension: USD 20
- 70mm extension: USD 25
Warranty
- 3-year manufacturer's warranty
- Any disassembly of the assembly voids the warranty.
- No repair, return or exchange possible in case of disassembly
Safety precautions
- Never use without an appropriate light reduction system for apertures >100mm.
- Forbidden for unsafe visual solar observation.
- Always check filter integrity before use.