hereby I submit an image for the AAPOD. It’s a HDR
picture oft he solar eclipse, from August 21, 2017.
In the following lines you can read the technical
and processing details and at the end why I have
decided to process the image especially in this way.
Image in appendix.
Recording date: August 21, 2017
Location: Corvallis, Oregon, USA
Lens: Astro Professional ED Refractor
(aperture:80mm, focal length: 560mm)
Camera: Canon EOS 700d
Gain (ISO): 100
Details: The picture is a HDR
(hyigh dynamic range) of 12 pictures with different
exposure values. Values ins seconds:
1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8,
1/4, 1, 2
Before totality of the solar eclipse I used an ND
5.0 solar filter foil. I removed the filter
immediatley after the begin oft he totality.
I started the image capturing with the
HDR-bracketing function of Magic Lantern for my
Canon EOS700d, triggered with a cable connected
The telescope, my ED80, was tracked with an older
Meade LXD-75 parallactic mount (Polar Alignment for
a perfect tracking was done early in the morning
(03:00 AM on August 21, 2017)!
The image processing was time-consuming. I need 14
days of work in the evenings to finally work out
this picture. My steps of image processing in
1. First control in lightroom, minimal first
sharpening for corona
2. Manual centering in Photoshop
3. Loading and Stacking in PixInsight 1.8
4. In PixInsight:
- Color calibration
- Histogram transofrmation (wihtout masks after a
lot of tries)
- HDRMultiscaleTransform with a scale of eight
- Curves transformation, adjustement of histogram
- Export to Tiff
5. Next steps in Photoshop:
- manual centering of hdr stack with stretched moon
from 2 seconds exposure-time image from this stack
- stacking and transformation (the moon was shrunken
in diameter – I had to correct it, due to sun light
„blooming“ after 2 seconds ecposure time)
- sharpening, noise reduction
As you can see – a lot of work and iterations to
work out such a picture.
I’ve done a lot of investigation on the internet.
You can find a lot of solar eclipse pictures as
reference. A lot of pictures are sharpened too much
(my point of view), e.g. with a Larson Sekanina
filter. But I’ve seen a lot of filter artifacts in
the picture details.
After my first tries in image processing I decided
to work out a more hamonic picture. The corona is a
little bit more faint but harmonizes more with the
sun/moon border and the background. The background
looks a little bit more gray-blue after color
calibration but comes more close tot he reality. All
in all this harmonizes more with the embedded
prominences but without loosing the glowing effect.
You can see the glowing from all perspectives! The
glowing is changing when you change your viewing
Therefore the picture shows a lot of part that you
couldn’t see with your naked eyes but preserves also
the visual impression during the total solar
I hope you enjoy the picture like me and it will be
chosen as an APOD.
If you have questions, don’t hesitate to contact me.
and many greetings from Germany,