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Tuesday, September 05, 2017

Lightning storm near Kitt Peak

Last night while waiting to observe on the 4-Meter Mayall telescope on Kitt Peak, a lightning storm passed to the southwest of Kitt Peak.  Here is some lightning to the southwest of the mountain with the Steward Observatory 90 inch Bok telescope building lit by the Moon in the foreground.  The image was taken with my Canon 6D with my 50mm lens at f/8, ISO 1600 with a 20 second exposure.

Saturday, September 02, 2017

Eclipse HDR and Earthshine

My eclipse photography plan during totality was to take a sequence of images with exposures tailored to see both the bright prominences and the faint outer corona, so my exposures were a set of 5 images every 5 seconds at ISO 200, f/7 (on my EdgeHD C8 with my Canon 6D and a 0.7x focal reducer) with exposures of 1/500 sec, 1/125 sec, 1/30 sec, 1/8 sec, and 1/2 second.  I used the same exposures on my Canon 70D with my 70-200mm lens at f/8.  Here are the result of some HDR combines using Picturenaut and then some touchup with the GIMP.

This is an HDR combine of 5 images taken with my Canon 6D attached to my Celestron EdgeHD C8 using a 0.7x focal reducer.

This is the same image as above but with some contrast stretching to bring out the Earthshine on the Moon.  I was hoping I'd be able to see it in the longest exposure of the sequence.

This HDR combine was obtained with my Canon 70D attached to my 70-200mm lens at 200mm focal length.  The exposures were made at ISO 200, f/8, and 1/500 seconds, 1/125 sec, 1/30 sec, 1/8 sec, and 1/2 sec.  You can see the dark blue sky along with the bright star Regulus to the left of the Eclipsed Sun.

This image is the same as the previous one but with some contrast stretching of the Earthshine on the dark face of the Moon.

Mount St. Helens

After seeing the August 21, 2017 Total Solar Eclipse, we headed for Mount St. Helens, the volcano in southwestern Washington that produced the largest volcanic eruption of the 20th century and the largest landslide recorded in history on May 18, 1980.  The eruption killed 57 victims as the north side of the mountain collapsed and blew out.  The landslide devistated a huge area mostly north of the volcano and an ash cloud rose to more than 7 miles, covering a huge area to the northeast of the mountain as the volcano lost 1313 feet from it's height.  The appearance of the formerly symmetric volcano was changed in minutes to a large horseshoe shape and over the next 6 years, a volcanic dome grew inside the crater atop the volcano.  Activity is greatly reduced but continues off and on, adding to the volcanic dome complex near the summit.

This photo shows Mount St. Helens from the north as viewed from the Johnston Ridge Observatory.  This location used to be called Coldwater ridge but was renamed after the May 18, 1980 eruption after the USGS geologist David Johnston who was killed during the eruption while manning some measuring equipment near this location.  His body was never found so he is almost certainly still very nearby.  It was a bit of an eerie feeling standing near Johnston's final resting place.  Johnston was one of the faces of Mount St. Helens during the nearly 2 months of volcanic activity around the mountain prior to the catastrophic eruption of May 18.

Spirit Lake was inundated by the landslide debris, sloshing water 800 feet up the slope of the hills to its north and burying the many cabins around the lake including the octogenerian Harry Truman who refused to leave the area despite the warnings of impending eruption under as much as 600 feet of debris.

This closeup of the summit of Mount St. Helens is the first of 3 images showing the horseshoe shaped summit left over from the eruption.  The clouds surround the summit area, especially the lava dome which grew after the eruption.

This second image shows the lava dome a little better. You can see a vertical column of steam rising from the vent.

Here is a closer view of the lava dome and the steam vent on its summit.

As we drove out of the park, we watched a pretty sunset over the mountain.

The magic hour around sunset produces some spectacular lighting and this day was no exception to that.

Wide field Total Eclipse shots

The following images were taken midway through totality using my Canon 70D with my 70-200mm lens.  The images used a 2 stop bracket with mid exposure of 1/30 seconds at f/8, ISO 200 and 5 total shots.  The images were taken in just over 1 second and I took a set every 5 seconds.  You can see prominences in the first image and increasing corona details as the exposures increase.  The final image also shows Regulus to the left of the Sun/Moon.