The arrival of a visible comet encourages me to learn astrophotography.

This is my first blog post in a week, and the first since our return from Switzerland. I envisioned writing a reflective piece about transatlantic travel in the time of coronavirus or about the re-entry into US culture, but we’re stuck halfway through a two-week in-home quarantine and there is a far more photogenic topic to describe first. Read on, and check out the gallery.

Comet NEOWISE photographed in Lyme NH. This photo is better viewed in the gallery.

Two weeks ago I stepped out of Diavolezzo hut into the dark night around 3:50am, as we began our climb of Piz Palü. I reflexively scanned the eastern skyline, its edge just beginning to glow, and immediately remarked “is that a comet??”. Little did I know, at the time, that it was indeed the newly discovered comet known as Comet NEOWISE.  I could not get a decent photo, using just an iPhone and with no opportunity to pause from hiking.

By the time I arrived home, one week ago, the comet was visible a few hours after sunset – rather than a few hours before sunrise – and I was determined to set up for a proper photograph. Last night was my third attempt, and the most successful. At 11pm I walked down to the river’s edge, where the night was still, the water calm, and the Vermont forest on the opposite shore glowed ever so lightly with the memory of a sunset more than two hours earlier. The Milky Way was spread overhead and the Big Dipper seemed to pour brilliant stars across the western sky. A few fireflies blinked busily on the lawn behind me, but thoughtfully remained out of my camera’s long-exposure view across the river. With no breeze, no bugs, and no evening chill, I stood there for an hour or more, soaking in the view and taking a couple hundred photographs. The only light was that cast by the stars above.

At one point I noted a dark shape gliding noiselessly upstream, about 10m offshore. In the darkness I could barely distinguish it from the water itself, despite the starshine glinting on the surface. The shape doubled back downstream, then again upstream, seemingly curious about the odd two-legged animal on shore. It came closer on each pass. Standing alone on the shores of this dark river, I admit that visions of underwater monsters from decades of movies from Star Wars to the Lord of the Rings crossed my mind. The creature came silently closer to shore, back and forth.

A dark creature swims upstream past me.

I’ve spent enough time on this river to recognize a friend when I see one. Despite the darkness, I was pretty sure I knew who had come to visit. I stomped my foot and… WHAP!! the beaver slapped his tail and dove underwater with a loud splash. He soon resurfaced and made a few more passes, inspecting me, before WHAP!! slapping his tail, this time unprompted; he silently slid off upstream to take care of his business. No real photograph was possible in the dark, but my attempt actually coveys the spooky situation quite well ;-).

Back to the comet. Over an hour I experimented with different compositions and exposure settings. My best results came with a common 16-80mm lens at 16mm, f/2.8 for 6 seconds at ISO 1000, compositing bursts of ten photos in the “Starry Landscape Stacker” app and then post-processed in Lightroom to reduce noise. I also tried my f/1.8 35mm prime lens, and my f/2.8 70-200m telephoto lens, but none of those photos looked quite as nice.

See the gallery for three full-res photos; I include only a sample at the top of this post. If we get another clear night, I may try again!

Author: dfkotz

David Kotz is an outdoor enthusiast, traveller, husband, and father of three. He is also a Professor of Computer Science at Dartmouth College.

2 thoughts on “Comet NEOWISE”

  1. the app made a big difference. I did not do dark frames, but now wish I did… there was still a lot of noise, and I had to dial up the Luminance noise reduction pretty far. I never found a good balance between noise and softness induced by the Luminance noise-reduction.

    I’m also unsure whether I should have gone for longer exposures at lower ISO, like 12s at 500 instead of 6s at 1000.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: