Total solar eclipse 2019 blog Joe Cali

WAITING FOR THE SHADOW

Solar Eclipse Observing and Photography - Joseph Cali

TOTAL SOLAR ECLIPSE
ARGENTINA - JULY 2, 2019

Monday 1st July, 2019.

Terry and I set Monday July 1st aside for preparation. We both set up our gear, did dry runs, made notes of procedures. Terry has a computer driven setup and had to get his scripts working. I have a set up that is just driven by intervalometers and manual control that I've used for many years, so I had a lot less preparation but needed to get my head around the procedure. During totality, I operate the cameras by touch only so I can spend the duration of totality observing naked eye. On Monday evening, we packed the car ready for an early departure if weather changes dictated a long-distance move. We prepared sandwiches and went and bought some fruit. We filled all the water bottles we had, some for drinking water, some for ballast and counterweighting.

Tuesday 2nd July, 2019.
We woke early to a mixed weather forecasts. The GFS model forecast was not great. However ECFWM and the G channel of ACCESS were predicting clear skies. In my experience, GFS is the worst predictor of cloud of the three models mentioned. Once we left, we would have no mobile phone reception so we delayed departure until midday then decided to ignore the GFS and go to our previously scouted location which was going to be clear according to ECFWM and the G channel of ACCESS. There was a bit of traffic on the road but we made pretty decent time arriving at 14:00, 2h24 mins before first contact.

Weather Model Acronyms

GFS
ECFWM
ACCESS G channel

Global Forecasting System
European Community Forecast Weather Model
Australian Community Climate and Earth-System Simulator-Global channel

I moved all my gear up to the little ridge we had selected and laid it out and started setting up.

I used my old trusty "alignment jig" that I have used at many previous eclipses for setting up the polar alignment. It worked a treat. Alignment only took a few minutes and the little Polarie tracked faultlessly for hours. Don't be fooled by the tee shirt. This was early in the peace and it was already cool. Soon after this picture was taken, I put on a long sleeved shirt and a thick insulated and windproof jacket.

Once the alignment was done I only had to attach the 300mm lens and K5 camera then attach the K1 and 50mm and the K01 and fisheye lens to my other tripods. Attach the solar filters and it was all done. The Polarie didn't drift much over the next 3 hrs. I thought that pointing the Polarie at the sun without slow motion controls might be a challenge but it was pretty easy. Then I was able to relax. I think Terry took a picture of me laying out on the foam mat, head resting on the padded camera backpack.

This is the part of Terry Cuttle's setup on the EQ3 mount. There were two
more tripods out of frame with several wide field and 360^o video cameras.

First contact came soon enough. We had selected our site (30°28'54.197" S 69°8'41.628" W) to give us approximately a 50km view across the plane to the first range of mountains and 100km to the Andes. The shadow, travelling at 3.4km/s would cover the 50km in about 15 seconds.

In contrast to 2017, this eclipse went fantastically well for me.

I concentrated on just four things.

Naked eye observation and three camera captures.
Fisheye movie of shadow transit.
300mm f4 EDIF lens with APS-C camera with intervalometer shooting 1 min interval partials. Then with the same optics, manually controlled sequence from 1/4000-4s sequence of totality using 4 sets of 5 step auto brackets.
50mm f1.7 with full frame camera also with intervalometer shooting 1 min interval partials then me shooting 4 sets of auto brackets. Very easy on this camera. I just press the shutter once with the camera set on each of 4 user modes I have setup with the whole bracketing sequence. It took about 20s to capture that whole sequence.

Both of my still image capture sequences went well and even before I had time to process radial composites, the raw files looked like they would yield good results. I reviewed the video soon after the eclipse and it did capture the sweep of the shadow quite well.

Terry had less success. He had a more complicated setup than me with about 7 or 8 cameras. He had 3 DSLR’s on an EQ3 tracking mount; one attached to a refractor for telephoto corona imaging, a second setup for telephoto video of the corona and a third attempting to capture a flash spectrum. He had two wide angle setups (imaging and video) on separate tripods, one towards the eclipse and the other facing in the direction of shadow departure, and a 360 degree camera. We had strong wind and the lightweight tripods he had on the wide angle setups were badly affected and he had to scramble to steady them. This took away time to get other things ready. The lightweight tripod I had was only 200mm tall and held the fisheye cam so it didn't get affected by wind. My other Manfrotto tripod holding the camera with 50mm lens was solid enough for that focal length and my 300mm on the Polarie tracker is only 500mm high and was just ok in the wind.

More of a problem for Terry, he left himself too much to do. He suffered the very same problem I did in 2017 where I overreached and tried to do too much and failed on most. He had problems with the intervelometer on one of the wide angle setups just before second contact and in attempting to fix that, didn't start some cameras, and removed filters too late from others, etc. He got some results but several no results on cameras. An unfortunate outcome for all the gear he lugged over. Nonetheless, from what I saw of his results, I think he will salvage much more from what he did get than I did 2 years ago.

Terry says that his philosophy in taking multiple cameras is that he can better tolerate failures. Terry asked me to, "be kind, when you write your blog." Having had the same thing happen to me, I am totally sympathetic and definitely not critical. These things happen, we learn from them and move on.

After watching the shadow approach, both Terry and I got an eyeful of a beautiful totality in skies that appeared to us to be remarkably clear despite the thick layer of smoke and dust we could see below us in the valley over Bella Vista. The corona hung in the sky over the Andes like a giant gossamer with dozens of delicate polar streamers being visible to the naked eye in exquisite detail. Our location was at 2260m elevation and some 300m higher than Bella Vista. Clearly we were not above all the air particulates but we picked a site that sat just above the thickest of the airborne particulates. We did see the shadow come across the smoke / dust layer. The ground was covered in dark grey fractured rock and was not conducive to shadow band detection. I certainly didn't see shadow bands and Terry has not mentioned them. I could just see the stars Castor and Pollux with some difficulty. The corona, typical of a solar minimum corona with long equatorial streamers and a myriad of polar 'brushes' and remarkably similar in appearance if not size to the corona I had observed in Bolivia some 1250km north of our location about 25 years earlier. The air at Lago Poopo at 4500m altitude was remarkably clear. Nonetheless, the air at our site SE of Bella Vista was crisp and clear, the corona brilliant and the diamond rings were sharp showing no noticeable signs of atmospheric scatter.

The partial eclipse finished within 1 minute of theoretical horizon sunset. However, the sun set about twelve minutes before this due to the Andes (6:30pm local). By the time we packed up it was almost 7:30pm and with heavy traffic the two hr return drive became 3hrs. 1030pm back in town, 11:30pm by the time we had some dinner, then packing up until 2am, 9am departure next morning for a 2.5 hr drive back to Mendoza where we caught an 8hr bus to Santiago Chile arriving 9pm. Then yesterday I went to the airport caught a flight to Calama and then drove to San Pedro de Atacama where I find myself now. I had a very big & much needed sleep-in this morning. I have 9 nights here in San Pedro so plenty of time to explore.

Photographic Results

First Contact

Totality

Above : Single image of the umbra, Pentax K5, Pentax 300mm f4, EDIF, ISO100, 1/60^th second
Below: The same image as above processed more forcefully in Adobe Lightroom

Ten years ago, I was playing around and found a way of enhancing major stuctures
albeit at the expense of fine high spatial frequency structures of the inner corona.

This composite image is made up from 12 different exposures ranging from 1/1000s to 2s at f4 using a Pentax K5 DSLR, Pentax 300mmf4 EDIF lens at ISO100

The Sun at totality with partial phases at 3 min intervals. The two stars in the upper right of the frame are Castor and Pollux while the fainter star at the 10 o'clock position is the 2nd magnitude double star Ahlena and above it to the left is 3,3 magnitude Alzirr and the in the 4:30 position is 3rd magnitude Mebsuta.

In addition to the thirty three partial eclipse images, five different exposures of totality were radially composited to show the corona from the limb out to approximately 5 solar radii from the limb. Fortunately, the two tiny clouds at bottom left were the only two clouds in the sky.

Third Contact
The rear edge of the umbra raced up from the horizon and a star was born. The diamond ring at third contact was particularly long lasting. I have no way to time it but it remained small and brilliant yet observable for many seconds. Terry and I both noted this in our post totality discussions.

The shadow passage
The umbra from our perspective swept from south to north or left to right in these photos. This is just an optical illusion, an artefact of the projection of the umbra onto the spherical atmosphere. It was of course moving from northwest to south east.

The umbra just after C2

The umbra at mid-totality

The umbra at C3

Time-Lapse Movie of the umbral passage
A 20 times accelerated time-lapse movie of the shadow passage can be seen here in 720p HD.

https://vimeo.com/346349490
The movie will open in my Vimeo page in a new window. Close the tab or window to return here.

YES!

High fives

Smiles all round

Eclipse jubilation was tinged with more than a little sadness before, during and after the eclipse remembering my close friend and eclipse chasing 'partner-in-crime' of the last 18 years and 12 eclipses, Bengt Alfredsson, who passed away last April after a long illness. Bengt, I hope you are reading this, at that big internet café in the sky. You were certainly missed, and this one is dedicated to you my friend!

July 3rd and 4th Crossing the Andes

There is nothing exciting about packing up, a 2.5hr drive, and an 8hr bus ride. But the ride thorugh the Las Cuevas border pass from Mendoza to Santiago is very beautiful as is the flight along the Andes from Santiago to Calama and then the 1hr drive to San Pedro.
I won't bore you with commentary. I'll let the pictures speak for themselves.