Baker's Dozen -- Diamond Ring 2017 August 21; Mid-Eclipse; Third Contact

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Photographer:

annewalker170

Location of Photo:

Clemson, South Carolina

Date/Time of photo:

2017 August 21 14:37 14:38 14:40

Equipment:

Nikon D300 12MB (4288x2848) cropped to 1000x1000 300mm F4 (stopped to F5.6) ASA 200 1/60 1/4 1/4

Description:

Brief Report on the Total Solar Eclipse of 2017 August 21 In 2000, my insisted(!) I view the total solar eclipse in Africa. "The Boss" said after we started our family, the only eclipse I could even think about would have to be within easy driving distance. The long wait of 17 years was over Monday. My wife, Anne (4 prior total solar eclipses,) three teenage children (0 prior total eclipses,) and one sister (1 annular, almost total 30 May 1984,) left early Monday morning to drive from Charlotte to view the eclipse from the Snow Family Outdoor Center of Clemson University. (One sister decided at the last minute to stay home as the predicted high temperature would be too much for her.) Traffice was not a problem, and we arrived at our viewing site shortly after 10 AM. We were later joined by our niece and a friend with an 18 month infant who had decided to drive down from Asheville that morning. The site and staff were subperb. We were under a large tent for public use near the top of a hill overlooking Lake Hartwell. We were quite comforatble in the about 90 degree weather, especially with a frequent breeze. The sandy beach was a little too far away for possible shadow bands, but a nearby gravel drive and a rack of flat wind surf boards would do. The weather cooperated nicely, and there were only some fair weather type cumulus on the horizon to make sure we stayed alert. Partial phases were observed through a small H-alpa telescope. The kids took a lot of afocal partial images using their smart phones. Almost everyone present were experiencing totality for the first time. They seemed really fascinated to see the solar crescents projected on the ground by crossing the fingers of both hands in a waffle pattern making several images at once, or simply making a single 'pin hole' by curling the thumb and fore-finger. Projecting an image on the inside of the tent by using a plain round UV filter as an unsilvered mirror was also quite impressive. The next time, I will try to bring a round mirror for this purpose. Impressions of Totality Second contact and totality finally arrived. As always,I did not look until the Sun was NOT visible in the filtered view, usually a #14 welders glass. (I know if I start looking too soon, I would simply keep staring until the first diamond ring and risk potential eye damage. As a result I only see the first diamond ring in photographs.) This was a very bright eclipse. Checking time on an LCD clock required no extra illumination. The inner corona was quite bright and symmetrical, almost like a spiky coronet. There were two spikes extending about 1 solar diameter at about 1:00 and 4:00, and a third fainter spike about the same length at about 8:30. There were some distinct shorter brushes at about 11:00 and 12:30 about 1/3 diameter in length. I do not remember much southern detail. There was quite a bit of fine structure visible in 8x40 binoculars, but in general, the corona was quite condensed and compact. As I do not remember the sky being a vivid blue before totality, there may have be slight haze which might have affected visibliy of fine detail. The H-alpha view alerted us to a prominence at 3:00 which would be visible during the last half of totality. We were not disappointed. The chromosphere before third contact was best in memory (of 12 prior total eclipses): it was quite bright and saturated with some beading on the cusps, and it seemed to cover 60 to 70 degrees of arc on the western limb just before being eclipsed(!) by the second diamond ring at third contact which all to rapidly became an ever expanding drop of molten silver signalling the end of totality. I did not see shadow bands, but a group next to us closer to the drive saw them on the gravel. I do not remember if this was before or after totality. Warp-up Amazingly, we remained bug free the entire time. The much feared traffic did appear after the event. A normally about three hour drive took about seven hours (including two stops.) This made us feel we were correct in picking a spot several days before the eclipse and planning to remaining put, rather than trying to relocate on eclipse day. Thousands, if not millions, of eclipse chasers trying to avoid an unexpected front may have resulted in the Mother of All Gridlock. A good time was apparently had by all, especially those first time viewers who now know observing a central eclipse from the under the umbra rather than under the penumbra is a totally different experience. To misquote Monty Python, now for something totally different. Do you think my wife will let me get back on the Eclipse Treadmill? Probably not until college is behind us... A Few Comments on Photography The eclipse (digital) photography gods decided to keep me anchored to reality, probably for getting rusty after skipping 17 years of eclipses. Maybe they prefer film. Two setups were planned. One was a wide angle sequence at two second intervals from about three minutes before totality to about three minutes after totality. The second was to shoot three sequences of nine bracketed exposures of +/- 5 EV to capture prominences, inner, middle and outer corona. Both cameras and lenses were set to function very manually (manual exposure, focus, white balance, ISO, etc.) and were tested several times on Saturday and performed as expected. However, on eclipse day, the first camera shot only one frame. And the second camera did not bracket the exposures. After some analysis, and skipping the probably boring details, both setups under performed due to simple IO error -- an Idiot Operator (who happens to be simple.) But the gods were not without mercy. Attached are three photos. All photos were taken with a Nikon D300 (APS-C format) using a 300 mm F4 (450mm equivalent) lens stopped to F5.6 at ISO 200 manual focus with white balance manually set to daylight. Original images are 12 MB (4288x2488). The first is the diamond ring at second contact (1/60 sec), the second is mid corona at mid-totality (1/4 sec), and the last is just before third contact (1/4 sec). The Sun was placed left of center to compensate for the approximate one diameter drift west that would occur during totality using an unguided mount. There is a star (?Regulus) visible about two diameters away about 9:30 in the second and third photos. In spite of the exposure, the last still shows some of the vivid red of the chromosphere visible immediately before the diamond ring as well as a hint of a prominence. Becoming one of the uncounted eclipse chasers who miss viewing an eclipse while concentrating on their equipment is not a pleasant prospect. Photographing the eclipse is optional; seeing the eclipse is not. Photos are always a welcome bonus. The goals may not have been exceeded, but they were met. Anne Walker / Timothy Shelton 1200 Greylyn Charlotte, North Carolina 28226 (704) 975-7999 [email protected]