Comet Comity

“Comets are like cats: they have tails, and they do precisely what they want.”     David H. Levy

Photographing comet Neowise; waiting for dark

Waiting for dark.

I've spent more time photographing in the dark this year than ever before. I'm not very good at it, although I've had some success (if that's measured by the number of “keeper” photos) with moon photography, but heck, quality moon photos are pretty easy if one doesn't mind working in the dark (and, sometimes, other interesting conditions). Inspired by local photographer John Ashley's wonderful night-sky photography I bought a fast 20mm lens a few years ago, but I've hardly used the thing, and not practiced enough to develop the skill or techniques. Nobody's fault but mine, of course. The way to Carnegie Hall? Practice, practice, practice. In this case, I haven't.

As I wrote in my May, 2020 article, “Moon Over Montana,” 2020 started with super moons in four consecutive months, February through May, and I'm happy with the pictures I made during the last two. Clouds socked us in on the appropriate nights in February and March, so I stayed in on those nights which, as I recall, were pretty darned cold.

July brought us comet NEOWISE*, named for the orbiting telescope that discovered the comet on 27 March. Officially called C/2020 F3, this cosmic snowball, visible only in the northern hemisphere, is about three miles (five km) wide and is constrained to orbiting our sun (in other words, it's not an interstellar object). If you want more science than that, spend some quality time with your favorite search engine. At first I decided to skip photographing the comet. There'd be lots of really great photos posted in all the places people post them, the newspapers would have more, and you can't beat NASA's photos. Of course, NASA cheats, having billions of dollars of pretty nice photo gear, both terrestrial and in orbit. But one evening Pat and I, sans camera gear, drove down to a city park on the lake shore, with wide open views to the northwest over Flathead lake and distant mountains. We had the park to ourselves; we could sit on a comfy bench and wait for dark and the comet to appear. Both did, and we very much enjoyed the view. And of course, I decided to try to make some pictures.

I knew there'd be lots of photos made of this comet. I knew some of them would be quite spectacular. Some would have terrestrial “stuff” in the scene, others only space and stars around the comet. I decided to try a little of everything but concentrate on having some earthly foreground in my compositions.

Things That Go “YIKES!” In The Night

I went out three times, the first on 16 July at about 3:30 am. Were I live, in hills covered with sky-scraping Ponderosa pines, there's no wide expanse of sky to be seen, so I drove a few miles south and east to a clear area near a local highway. I parked, stepped out of the car into early-morning silence under a clear sky and billions of stars. The waning moon had not yet risen above the Mission Mountains beyond Flathead Lake off my right shoulder (east), giving me an inky-black sky. I spotted the comet instantly, brilliant above distant trees somehow blacker than the sky. I set up with my long zoom lens set to 400mm, made a few test exposures and found they looked better, on the camera's display, than I had any reason to expect. Minutes later the moon rose, but had little impact on the scene. I played with both horizontal (landscape) and vertical (portrait) framing; as I worked the sky began to brighten slightly. I exposed for the brightest, longest comet tail and let the rest of the scene fall where it would on the exposure scale, which means various levels of blue-black. Excited by what I saw when chimping, something I rarely do, I continued to work until the first traces of dawn light started dimming the comet. (I normally take a quick glance, after most shots, at the camera's display to see the histogram, in my opinion one of the great benefits of digital image capture. But in this case I knew the histogram's values would be jammed against the left side, all dark pixels, so I switched the display to show only the image. I had no worries about missing the shot; there's not a great deal of action when photographing a comet!)

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Comet Neowise, with barely visible trees on the horizon.
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Comet Neowise above last light on the horizon.
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Comet Neowise and starry sky, the 'generic' photo.

This was only my first attempt, and the comet would be visible for a few more nights. Tired but eager to see these pictures on my computer monitor, I hoped to learn what I did right and wrong to improve my next attempt. Of the pictures from that first night (morning) I had several good ones of sky, stars, and comet. But only a single frame captured what I really wanted: sharp foreground trees very dark against a slightly lighter sky of stars and comet. With an exposure of several seconds, even at high ISOs, at 400mm, the stars blurred, “stretched” slightly, exactly as expected. Not ideal, but not terrible.

The next attempt came two nights later, starting about 10:00 pm and ending around midnight. Where I live, in northwest Montana not far from the western edge of the Mountain time zone, the July sky is still fairly bright at 10:00. The sun had set but a little warm color remained just on the horizon under a perfectly clear sky. I'd walked down the hill from my house and then climbed to the top of the ridge I described in the moon article linked in the first paragraph above. I found a foreground scene I liked, and then adjusted my position so the comet would be in that scene above the trees. The terrain up on that ridge is a little rough, with no easy place to sit, so I wandered around for an hour or so, waiting for the sky to darken enough to provide good visibility of the comet's tail. I then worked with various exposures, ISO settings, and tripod positions until I felt I'd done all I could. My headlamp guided me back down from the ridge and home to bed.

An interesting tidbit: during this summer there have been reports of a mountain lion prowling the area. I hoped to see it, but not while out alone in the dark on a high ridge with iffy footing. I spent my nights not just on the edge of that ridge, but also on edge listening for the sounds of any animal roaming through the trees and brush on the ridge. I heard deer not far away, but I neither heard nor saw any evidence of big cats. Of course, they're pretty stealthy and I might not have.

I downloaded those pictures to my computer the next day and looked though them, finding nothing I could keep. It was, however, pretty clear what I needed to do to fix the problems that sent all of those images to the trash, so three nights later I climbed the ridge again, at about 10:30, and set to work. As midnight approached I could see nothing. Without my headlamp I could barely make out my camera and tripod, so complete was the darkness. At one point I turned around and nearly ran into a little whitetail buck not three feet away. We scared the dickens out of each other, the deer bolting straight down from the ridge, me just about jumping out of my shoes (and other things). By then I'd already gotten the photo I most wanted. My heart rate eventually slowed to near normal and I finished up. I had better luck this time, using what I'd learned from the previous session to get decent exposures of both foreground (for color and detail) and the dark sky higher above with stars and comet. Those results are my best photos of the comet, I think, and worth the effort and brief moment of terror to get.

Not The Best, Not The Worst

NASA quality? Hardly. Astronauts made some beautiful photos from the International Space Station. I later saw some photos by local folk (including John Ashley) that showed the comet in a sky filled with colors of the aurora; I saw no trace of that, but some of those people did a great job capturing really dramatic pictures.

If you didn't see Neowise you'll have another chance in about 6800 years. Mark your calendar!

* NEOWISE: “Near Earth Orbit Wide-field Infrared Survey Explorer.” Just another space machine subjected to NASA's tortured naming schemes. I suspect they have teams of people whose job is to invent an acronym and then make up a vaguely descriptive phrase that fits it.

August, 2020

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