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Time Out for Alaska
the solar eclipse edition

3/4-15/2016. You have no idea how many times these entries are going to be rewritten, so I might just as well get the basics down and get started.

Jessica Smith and Logan Kraus are getting married. Not right away. Next summer. I've shot both of Jessica's sisters' weddings and some engagement folios and senior portraits, and Jess wanted to continue the tradition. Which is a challenge 'cause she lives in Anchorage. But not that much of a challenge 'cause American Airlines can get me there from Charlotte in under 12 hours and, hey, for coach fare and a couch, I'll go a lot of places, Alaska most certainly included. So for two weekends and a few days in between in the spring of 2016, I was Jess and Logan's paparazzi (what is the singular?). I'll eventually post some of the work I did for them, but fair's fair: they get exclusivity for that, to use as they see fit, and I don't want to scoop their shots for family and friends here. But the rest of it — eclipses and mountains and rivers and northern lights — we're going to have some fun with that.


This is primarily an astrophotography 'blog, so let's start with the solar eclipse of March 8-9. The umbral shadow of the Moon crossed Indonesia and the width of the Pacific Ocean. It crossed the International Date Line (hence the dual date) and left the Earth just before reaching the Americas. The Pacific is a big place, and even though the penumbral shadow stretched out thousands of miles from the path of totality, it touched land on the American continents in exactly one place: south central Alaska. Where I happened to be.

Logan suggested Point Woronzof Park, where a paved parking area overlooked Cook Inlet at the end of Northern Lights Boulevard, out beyond Earthquake Park (under the departure path for Ted Stevens International Airport, ANC). Perfect. The tide flowed in while we waited, an Amazon of ice-flecked seawater moving at a walker's pace from the open Pacific toward Anchorage.


Cook Inlet

Go on, click the image for a better look.


The Moon obscured 18% of the Sun at the height of the eclipse, but clouds hid 100% of both until almost 20 minutes later. The Sun peeked from under a heavy overcast still slightly eclipsed for only a few minutes before setting behind the Chigmit Mountains, 90-100 miles away. When it sank into clear air below the overcast, it emerged with full noon-time brilliance, not in a hazy setting-sun irradiance but in a blaze of arclight.




If Lake Clark National Park and Preserve were ground zero for a 50 megaton bomb, you would see something very much like sunset on March 8 over Cook Inlet.

I was prepared for the eclipse with a 70-200mm Canon lens, a 1.4x extender, and the 6D body, but I was not prepared for the abundance of sunlight. By lowering the ISO to 50, closing the lens to F45, and shooting at 1/4000 of a second, I could compose using live view and just retain details of the eclipsed Sun, and, with some HDR techniques, keep the serrated mountain crest in view, keep the brilliant path of the Sun on the Inlet's waters, and keep distant clouds encircling the Chigmit Mountains' peaks:


eclipse HDR


Solar Eclipse Alaska

Solar eclipse over Cook Inlet
1/4000s, F45, 70-200mm F4L IS + 1.4x Extender
Canon 6D, ISO 50
(click the images for better views)


I had the Canon and its modest lens set up on an Induro carbon tripod (first light for that 100% excellent piece of gear). Other visitors came and went, but only one other (maybe two) seemed aware of the eclipse. Most came to admire the sunset. One gentleman a little farther south shared the edge of the parking lot: Matt Skinner, Lights Out Photography, set up a 6-inch Celestron reflector on a light equatorial and shot through a filter with a Canon 5D Mark-II. Our images are remarkably similar considering the difference in hardware. There's a chance that we alone saw the eclipse from this side of the Pacific.



While waiting for the Sun to sink into the clear air below the heavy overcast, I spent a lot of time inspecting the far side of the inlet using the 70-200mm telephoto lens. A fine, dark line ran just above the water; it was darker and more prominent around to the north and east, finer and less conspicuous toward the west, and finally absent when looking almost due west. (You can just make out this feature on the right side of the two-frame sunset panorama up above.) Aim the 280mm focal length of the extended zoom across the water; crop the image at full resolution; and have a look. If this were the camera's full field of view, it would be equivalent to the view through something like a 2,800mm lens:



The line resolves into a forest, mostly spruce, mind-warpingly extensive, and very likely not too different from the one through which we drove to reach Woronzof Point. The image above is cropped from this one:

cropped field

The mountain is Mount Susitna, 27 miles away. The shoreline is about 8 miles away. Look again at the bright orange panorama of the setting Sun. See how the fine line of the forest fades away? It isn't distance per se that renders it gradually invisible as the far side of Cook Inlet trends away to the west. The forest disappears below the convex surface of Cook Inlet. The inlet's waters follow the curve of the Earth. The sagitta of the water hides the forest beyond. The distance to the farther shore varies from less than 10 to something over 100 miles from Woronzof Point. Somewhere along the way, the curve of the Earth erases the forest's profile. Think of the masts of a million sailing vessels disappearing over the horizon. (There are other photos "in the can' that may illustrate this directly.)

This must be the clearest air I've ever encountered. Distances are always greater than they seem.


Next page from Alaska




Except where noted, deep-sky photos are made with an SBIG ST2000XM CCD behind a 10-inch Astro-Tech Ritchey-Chretien carried on an Astro-Physics Mach1GTO. The CCD is equipped with Baader wide- and narrow-band filters. The internal guide chip of the CCD most often keeps the OTA pointed in the right direction (I'll let you know when an OAG or guidescope takes its place). Camera control and guiding are handled by Maxim DL 5.12. The stock focuser on the AT10RC has been augmented with Robofocus 3.0.9 using adapters turned on the lathe downstairs. A Canon 6D and a modded 50D find themselves mounted on an Orion 10" F4 Newtonian or carrying widefield glass on an iOptron Skytracker. Beginning in May 2013, PixInsight has taken over more and more of the heavy lifting -- alignment, stacking, gradient removal, noise-reduction, transfer function modification, color calibration, and deconvolution. Photoshop CS4 et seq and the Focus Magic plugin get their licks in, too.


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                   © 2016, David Cortner