An 80mm F=440mm, ED refractor was fitted with a Thousand Oaks Type 2+ glass solar filter and mounted on a Celestron AVX mount.
A Raspberry Pi computer was attached to the scope along with its power supply. The Raspberry Pi was running an INDI server. The mount and the Pegasus FocusCube v2 focuser were coupled to the Raspberry Pi and AstroDMx Capture was able to control the mount and the focuser via WiFi and the INDI server.
An SVBONY SV705C OSC camera was fitted with a Baader green continuum filter and placed at the focus of the refractor. AstroDMx Capture was used to nudge the solar image into the desired position on the preview screen and brought the image to focus using the Pegasus FocusCube v2.
AstroDMx Capture was used to capture a 2000-frame SER file in Mono 8 mode in an arbitrary ROI.
An advantage of the SV705C in this configuration is that the large sensor is able to capture the whole solar disk, liberating the user from having to make a mosaic. Even with a longer focal length scope, fewer panes would be needed to image the whole disk.
The double stacked Baader green continuum filter is particularly effective with refractors. The red and blue ends of the spectrum are completely excluded. The central wavelength of the filter’s 10nm band-pass is 540nm where the telescope optics are sharpest and free from chromatic aberrations.
The best 75% of the frames of the SER file were stacked in Autostakkert!, wavelet processed in Registax 5.1 and post-processed in the Gimp 2.10.
The Sun in green continuum light
The SV705C performed well as a 'white light' solar imager even when imaging through a 10nm band-pass narrowband green continuum filter, which selects a region in the middle of the visible spectrum.
