The Solar Spectrum Solar Observer series (SO) are narrow bandpass Hydrogen-alpha solar filters for observing or imaging the Sun’s chromospere.
Solar Spectrum H-Alpha rear mounted Solar filter system.
The SO 1.5 series has a filter clear aperture of 25mm which will allow a full disk view of the Sun with telescopes up to approx 3" at the required focal ratio of F/30 (~2200mm focal length). The filters are available in three bandwidths, all of which are capable of observing broad band features like prominences and flares, but are narrow enough to observe the Solar chromosphere. The list below will help you select which bandpass to choose which depends on what your primary solar interests are:-
- The 0.65A filter is a good choice for general solar study allowing you to see the solar prominences as well as active areas and filaments on the solar disk.
- The 0.5A filter will give you more contrast on the disk and excellent views of prominences and their fine structure.
- The 0.3A ultra narrow filter is for maximum contrast is desired for the solar disk features and the prominences will become more pronounced as they arch over the limb; features that were barely visible at 0.5A will show greater of detail.
The SO is housed in a low voltage temperature controlled Thermo Electrically Cooled (TEC) oven, with temperature tuning, which operates at 12 volts D.C. A cable is provided with the filter that allows the use of a 12-volt car battery for field use. It also comes with a power supply with a wide range of input voltages from 85 – 265V AC, to give the necessary 12V DC output.
Please note: an additional front mounted energy rejection filter is required for your telescope.
||Visual solar observation and imaging. Requires additional D-ERF Filter
|INNER DIAMETER / CLEAR APERTURE (MM)
||0.65 +/- 0.05 Angström
Solar Spectrum Narrowband Filter System Overview
Solar Spectrum Operational Instructions
Notes on the safe use of Baader Energy Rejection Filters (ERF)