Sun

The Sun is imaged in both, white light and in the spectral line of Hα. To obtain sharp images in white light, using a Baader filter (only 1/100000 of the light passes it) in front of the telescope aperture and very short exposures (1/4000 to  1/2000 seconds with the Canon EOS 1100Da) is appropriate. In the Hα line, use of the ZWO ASI 178MC is indispensible because of the low brightness produced by the Hα filter. So the technique is the same here as is being used for planetary photography. Hα images of the Sun are taken with the Televue Pronto.

Sun on June 9, 2014.

Canon 1000Da with Maksutov-Newton, exposure 1/4000 seconds with ISO100.

Sun on June 11, 2014.

Canon 1000Da with Maksutov-Newton, exposure 1/2000 seconds with ISO100.

Sun in the light of Hα. Image taken on May 15, 2019 at 16:21 CEST with ZWO ASI 178MC and Televue Pronto. Effective exposure time 3.5 seconds. Flares and prominences are clearly visible.

Sun in the light of Hα. Image taken on April 4, 2020 at 15:51 CEST with ZWO ASI 178MC and Televue Pronto. Effective exposure time 3.9 seconds. Also here, flares and, at the Sun's limb, prominences can be seen.


On the occasion of the partial solar eclipse on June 10, 2021 I have refurbished my 50 years old refractor. I had devised the projection screen at the time in such a way that I could superimpose a coordinate grid for any orientation of the sun, onto which I drew the sunspots with a sharp pencil. Still today, the projection works pretty well as can be seen here.