Partical Eclipse
Though not as splendid as totality, partial eclipse phase is still very beautiful, especially when there were some sunspots visible. The sun has been mostly inactive this year and was almost completely blank a couples of weeks before the eclipse. But one group of sunspots emerged and moved to the center, and then another group emerged near the edge of the Sun 2-3 days before the eclipse. The sunspots not only looked beautiful, but also was very useful for focus, as it would be very hard to focus on the edge of the Sun.
The following 2 composite images show the progress of entire eclipse, one was taken by Canon T3i and another by 5D4.
Baily’s Bead
Here are the two images of Baily’s beads composite. Each combines images taken at 3fps around C2 and C3, it looks much much more astonishing than individual image. C2 is on the right side and C3 is on the left.
Corona
The high dynamic range of corona requires multiple exposure covering 10 stops or so. The following are a few images of stacking different exposures.
I use two different processing approaches:
- Photoshop
This is traditional approach that can be found in many online tutorial. The basic flow is:
- Align all exposures. I skip this step since the Moon is moving, we should not use the Moon as reference. I used a very good equatorial mount with accurate tracking, so there is no need to align the exposures.
- For each exposure:
- Crop the image so the Moon is in the center, we call it image_crop
- Use Radical Blur to blur the image, we call it image_blur
- Generate high frequency of each image: image_high_freq = imiage_crop – image_blur + offset (I use offset of 64, but it should not matter)
- Stack and average all image_high_freq, we call it corona_high_freq
- Stack and average all image_crop, we call it corona_low_freq
- corona = corona_high_freq * corona_low_freq
- Pixinsight
This is a much simpler approach by applying LarsonSekanina on averaged exposure.
The following two images are processed with Photoshop. The 1st image has more contrast. You may also notice that there are some green color in 1st image, it is artificial effect, I think, of the radical blur of prominence. It can removed by using color range filter.
This is processed using Pixinsight.
The following two images were taken by 5D4, thus have a much wider FOV. 1st one is processed using Photoshop and 2nd is using Pixinsight.
Wild Angle
The following is wide angle composite of entire eclipse. The partial phase was taken every 5 minutes, using Manual mode, 1/3200s, f7.1 @ ISO400, however the totality was taken with Aperture Priority mode, f4, -1 EV for dark background.
The following wide angle image was take at C3. The plane probably carried people to watch eclipse from air.
Since during totality the Sun was high in the sky, the Moon shadow was not obvious as when Sun is low. The following animation consists of 6 images, taken every 5s from C2, it clearly shows the Moon shadow moving from west (right) to east (left).