Part 8: Solar Eclipse

20170817-21

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The Trip

We spent the night in the Craters of the Moon area (actually a remote camp at Fish Creek Reservoir) and then headed out to find a viewing area. We were a "little bit" early, but we felt confident that we could find a place that was both nice and "under-subscribed". Kathleen found a place worth checking out at Kelley Island right on the Snake River. They had a nice spot with plenty of room and shade trees right next to the river, so we changed our plans and decided to hang tight for a few days. Good thing we did as our "first choice" was in central Wyoming close to nothing with no shade. This worked out much, much better.

With one exception, the photos below came from my 42 megapixel Sony A7RM2 camera attached to a Lunt 60mm solar telescope with a hydrogen alpha filter. A 2x Barlow extender was used to provide a total focal length of 1000mm. The scope/camera were mounted on my Astrotrac tracking mount.

Any of the photos below that are pale orange/white were the result of extensive digital post-processing. PIPP was used to crop and normalize the images and write intermediate results to TIFF files. These TIFF files were then read with Autostakkert 2, stacked and sharpened to produce the final image. Stacks were between 40 and 100 raw images.

The Photos

The photos below are what we saw.

This stack of 75 was shot the day before the eclipse as a practice run. Sony A7RM2 at 1/50 sec, ISO 100 at about f/8 (whatever the scope with barlow provides for aperture).

A few minutes before the start of the eclipse. All of our stuff is out and ready to go. Kathleen is using my pro Canon 1DsM3 with 28-300mm lens.

This stack of photos was taken just before the start of the eclipse. Note the sunspots and the pattern of the surface around them.

About 5% of the surface is occluded by the shadow of the moon.

30% occlusion.

As the moon blocked more of the sun, it was starting to get cooler. Note the slight blurring near the moon's edge. This is a result of the stacking process not knowing what to do with an edge that is in motion from frame to frame.

About 50% involvement.

Perhaps 75% coverage.

The photo above came out of Kathleen's Fujifilm X-Pro2 with a 23mm lens. The camera takes great photos, but 23mm is just way too short, but it DID get a photo of totality. Note the purple fringe which is a great example of chromatic aberration present in most lenses.

The photo above was compliments of Randy Begger from Bozeman, MT. Randy and his family were camped next to us and he had the correct equipment to capture the totality.

Here is where things started to get tough. The filter on the scope blocks light so you can photograph the surface of the sun. But, with all that light gone, the only thing that remains is the outer edge of the sun. The photo above is NOT a stack, but rather a single photo from the Sony. Note the slight blurring which is due to the atmospheric distortion. Stacking normal removes the blurring, but since this photo is not stacked, you get what you get. In an ideal world, had we know the specific course of events, we would have had an additional camera without a solar filter to capture the totality. Kathleen was using the other camera with solar filter and in my setup, the scope IS the filter, thus not removable.

The corona is visible around most of the circumference of the sun.

A few seconds later the flares on the lower portion of the surface became visible.

These are huge flares, many earth-diameters high.

Stacking does not work in these situations, so one has to accept the blurring of individual images.

The flares were impressive, even blurry.

Almost at the end of totality, the halo is starting to appear.

Totality + 5%. The flares are still clearly visible.

Later, the sunspots became visible.

The stacking helps eliminate the atmospheric blurring and provide improved detail. The flares are now crisp.

Note the patterns around the sunspots.

About 15% still occluded. Flares are still clearly visible around the circumference.

About 10% left.

Goodby eclipse. This stack did not come out as crisp because fewer photos were used, thus less sharpness.

The totality was breathtaking and despite not being fully prepared with equipment to exploit that brief moment, we did watch it with our eyes. One of nature's true wonders. Odd to think that in the old days eclipses were used by shamans to assert power over their tribe. Today, eclipses are a monument to the predictability of planetary movement as eclipses can be predicted thousands of years into the future with extreme accuracy.

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