WAITING FOR THE SHADOW
Solar Eclipse Observing and Photography
- Joseph Cali
TOTAL SOLAR ECLIPSE
ARGENTINA - JULY 2, 2019
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
2nd July, 2019.
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
Weather Model Acronyms
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 360o
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.
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.
- 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
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
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
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
sympathetic and definitely not critical. These things happen, we
from them and move on.
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
above the thickest of the airborne particulates. We did see the shadow
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
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
The partial eclipse finished within 1 minute of theoretical horizon
sunset. However, the sun set about twelve minutes before this due to the
(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.
Above : Single image of the
umbra, Pentax K5, Pentax 300mm f4, EDIF, ISO100, 1/60th
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
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
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
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.
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
The shadow passage
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.
umbra just after C2
umbra at mid-totality
umbra at C3
Time-Lapse Movie of the umbral passage
20 times accelerated time-lapse movie of the shadow passage can be seen
here in 720p HD.
The movie will open in my Vimeo page in a new window. Close the tab or window to return
Smiles all round
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,
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
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