Experiencing the Total Solar Eclipse of 2017

By Sheldon Greaves

I’ve always wanted to witness a real, live total solar eclipse, but never had the opportunity until one came waltzing through our back yard. In short, it was totally as cool as the hype suggested, perhaps moreso. If you have not experienced one (and you don’t “see” a total solar eclipse, you experience it), you owe it to yourself to do whatever you must in order to be in the right place at the right time. It is truly unlike anything else.

My spouse, Denise, who photographed the eclipse through a Celestron C90 hooked to her DSLR.

There are many good reasons why these events evoked such awe and fear throughout history. Just before totality, the light takes on the color of twilight, but the shadows are short; the angle of the light that normally signals the start of end of day is just wrong. And then totality hits. In a matter of seconds, day becomes night, summer turns to winter with a 20-degree temperature drop, the sky ripples with the subtle hues of the chromosphere. There is still light, but it isn’t daylight, or moon light. Birds start their confused evening calls, often there is a sudden breeze. In our case, some odd, high-altitude clouds formed in the east just before totality, then went away after it passed.

In ancient Mesopotamia, the omen series inuma anu enlil is a catalogue of astral omens listed on roughly 70 clay tablets. Among them are many omens associated with solar eclipses. Generally, they were considered bad news for the king and led to an unusual institution called the šar puchi or “substitute king.” When a solar eclipse portended the death of the king within some period of time, the palace would have the king step down in place of some poor idiot who got to be “king” for the allotted period and then duly executed. However, on one occasion when a royal gardener was pressed into service as the substitute king, the real king died, and the erstwhile gardner remained on the throne.

Friends and family watching the partial phase.

It was a merry gathering at our home in Albany, Oregon. We had no less than nine house guests; my brother-in-law and his family, plus some friends from the Bay Area. It was the first time we’d entertained house guests in a long, long time (largely owing to not having a house or an apartment where we could do this), so there were a lot of logistics to take care of, from food items to setting up a guest wifi login. But it was good to see these people, some of whom we hadn’t seen in a long, long time.

For many years, my spouse Denise had always been the serious photographer. She is an immensely talented nature photographer, specializing in nature on intimate terms; closeups of wildlife, mostly birds, but especially dragonflies. I have learned a lot from watching and assisting her on many a field trip to nearby nature areas or when on vacation.

Transit of Venus near sunset, 05 June 2012. Photo by Sheldon Greaves. Click to enlarge.

Preparations

My track record in photographing astral phenomena is spotty at best, and not always because of bad weather. Early efforts to photograph lunar eclipses resulted in images that looked like a dim headlight out of focus. The annular eclipse of 2012 that was visible from California was my first serious effort and the results were mixed. There were clouds, which didn’t help, but we had fun and my spouse did get a couple of interesting shots. We had much better luck with the transit of Venus the same year, which involved chasing the sun by leapfrogging from one venue to another in order to keep it in sight. The day ended on the deck of some very good friends of ours who owned a beautiful home with a view of the beach.

This time, I wanted to be ready to take some serious pictures. My preparation began by attending a workshop on the eclipse held at the Corvallis Public Library last May. Some seasoned amateur astronomers offered some good advice on taking pictures, but also urged us to not turn this into a mere photoshoot. As I said before, this is something to be experience.

The Nikon D40 DSLR

I borrowed a Nikon D40 DSLR from Denise, who had long ago upgraded to something more advanced. The D40 takes shots of ten megapixels, which is a little on the low side, but plenty for my purposes. The problem was I had never used a camera like this, so I had to wade through the documentation, which insists on covering every little feature all at once. According to the astro-gurus at the workshop, auto features don’t work for eclipse photography, you have do do everything on manual. That meant settings of ISO 100, f/5.6, 1/125th of a second. However, my camera’s lowest ISO was 200, so I learned about the fiendishly clever system of ISO and f-stops that let you easily convert to different apertures and sensitivities for different situations and desired effects. In my case, that meant ISO 200, f/8, and the same shutter speed. The camera has an 8GB SD card, which according to my calculations would hold something over 1,000 shots, so I could basically shoot away to my heart’s content.

There was also the matter of the lens. I have a 220mm zoom lens for this camera, which doesn’t produce a huge image of the sun, but that was fine because I wanted to get the surrounding coronal fireworks. The other advantage of a smaller image in the viewfinder is that it takes longer for the sun to slip out of the frame. My tripod didn’t have a tracking drive to hold it on target, so I’d have to do adjustments manually.

Then there was the matter of a filter. During totality, there’s no need for a filter, but you absolutely need one for the partial phase before and after. I didn’t have time to find a filter to fit my lens, so I cobbled together a homebrew version using some mail-order mylar filter material. The body of the filter was cut from a dollar store water bottle. The inner ring holding the filter material came from the lid of a bottle of Pace Picante Sauce (Medium), and a strip of rubber tubing served as a gasket to keep the filter from falling off at inconvenient moments. It performed quite well for a jury-rig.

I spent some time in the weeks prior to the eclipse in the backyard, practicing lining up the sun in the viewfinder, then looking to see how far in moved through the frame over two minutes, the length of time the eclipse would last at our location. It turned out that no positional adjustments would be necessary, although I did check the focus a time or two. I also wanted to use a remote control to trip the shutter, but my camera didn’t come with one. Fortunately, as they say, there’s an app for that. I found and installed an app on my Samsung Galaxy smart phone that controls several different brands of DSLR. My plan was to hold down the button on the remote, or program it for one shot each second, then let it do the shooting while I watched the show. While it did work, I discovered in my practice sessions that when the camera faces direct sunlight, the heat of the sun spams the IR sensor on the camera so it can’t detect the remote unless you hold it right up to the sensor. I thought this wouldn’t be a problem during totality. The remote didn’t work, so I just manually held down the shutter for continuous shooting, and hoped that it didn’t throw things off. It didn’t.

The practice sessions paid off in the end. By doing a couple of sessions at about 10:17 AM, the time the eclipse was to start, I knew where in the sky it would happen, and whether my tripod would tilt up that high.

All told, I ended up with nearly 300 frames, a little over 100 of which were taken during totality.

Processing the Pictures

I knew that because astrophotography takes place, well… in the dark, one uses either long exposures or lots of short exposures averaged together to get a good image. This is what more advanced digital cameras do when they use “burst” shooting for low light conditions. The onboard computer does all the processing for you. My camera didn’t have that feature, and I’m not sure it would have worked even if it did. All that automatic stuff seems to crap out under lighting conditions as different as those for astrophotography, including eclipses. However, there is a wonderful free program for Windows machines called DeepSkyStacker that takes a whole bunch of sky photos, lines them all up, averages out the background noise, and brings out the details that are invisible in any single frame. I didn’t try using any of the more advanced options, but the basic output from several sets of frames, ranging from as few as fifteen to as many as ninety, gave me some remarkably nice images:

 

I hope to get some more images soon. One problem I encountered is that DeepSkyStacker produces 16 bit TIFF files, and my copy of GIMP only handles 8 bits. So I need to find heftier graphics software before I see if there are any additional enhancements I could make.

Generally, things went well. I’m pleased with the results even though I was not using a particularly up-to-date camera (I noticed, while preparing this post, that you can by a D40 for $74.00. When they first came out in 2006 they cost $499.00). If nothing else, I found out what one can do with older equipment, which is quite a bit.

I will also never look at the sky the same way ever again. That alone made the whole thing worth it.

 

 


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