Sonnenflecken / Sun Spots - 20211223

Milky sky whole day long, thin high clouds driven by strong winds in addition. Not a single minute of clear sky around the sun. I was intrigued by the early morning images presented on SolarMonitor.org:numerous small spots and some bigger ones which I already spotted yesterday - now much better in sight ...

Please consider comparing my result with NASA's continuum photo from this same day and time.

Despite the disappointing atmospheric conditions, I tried 4 times to get some useful images over the day. Sunrise here happens ~09:30h in the winter when the sun rises along a mountain's ridge. Then a big tree (without leaves) follows, so I went outside and started my first session ~10:00h (CET).

0. Capture time was ~10:00h to ~10:30h
Not the least chance to get some details on the sun's surface due to extended thin high clouds passing in front of the sun all the time.

The sun disk was visible but with it's light diffused by the passing clouds. At the same time these clouds lowered the contrast so the smaller sunspots remained invisible. Even the first stacked image set of ~150 frames only showed a single spot – the darkest one, on the left side. It's umbra looked very washed out and grayish, the penumbra was invisible. Nothing helped to bring more detail into view – there was none.

I deleted all RAW images ...

1. Capture time was 115323h to 115416h CET (F=420mm + f/5.6): 160 photos @ 1/1250s + ISO100

The sun looked brighter and clearer, but nevertheless thin veil clouds passed by all the time ... again, 160 frames did not yield a useful stack.

2. Capture time was 120725h to 121150h CET (F=420mm + f/5.6): 370 photos @ 1/1000s + ISO200

Same as 1. capture time but the sun was almost invisibly dark on the single images, so I had to increase the exposure time and also raised the ISO setting. 1/1000s seemed rather long with the clouds in addition to the bad seeing.

3. Capture time was 132911h to 133125h CET (F=420mm + f/6.3): 240 photos @ 1/1600s + ISO100

On early afternoon the sky turned a bit more from gray to lightgray-blueish, with thin clouds continue to pass by. Nevertheless, I could switch my camera back to my standard exposure setting for sunspot images: ISO100 + 1/1600s + f/6.3. From this series of 240 photos I could achieve today's photo shown here.

Compared to my sunspot image from yesterday this one of course shows less fine details.