Friday 27 July 2018

The Time Between: A Look Through the Eyes of an Astrophotographer

It is the hottest time of the day during the hottest month of the year in Montana, but two hundred feet above me a pair of nighthawks sense a change. They dive and twist with a grace somewhere between fighter pilot and falling leaf, air buzzing through their wingtips, raspy calls beckoning night, commanding the sun to set. The single, sand-rock knob that I sit on here in the prairie while I watch their aerial display will hold the heat I feel through my jeans well into darkness.

I wipe sweat from my brow and put my back to the sun as it inches closer to the Crazy Mountain Range seventy miles west of me. The air is touched with haze and a tangible stillness as strong as the scent of sage envelops me. There is contentedness all around — young birds have fledged, coyote pups are hunting mice on their own, wildflowers have bloomed and gone to seed, and for a moment the world hangs on the edge of seasons, its feet planted hard in summer, unyielding for now to the noticeably shorter days.

The shorter days — or more precisely the longer nights — is the reason I’m here. I’ve come to photograph the night sky. To capture during darkness the universe above our world, showing the same stars our very first ancestors looked up at. I’m stepping outside the comfort zone defined by enough light for my eyes to focus, invading the time between sunset and sunrise, when, since those same, stooped ancestors placed fire at the entrance of the caves in which they slept, no human has ever felt quite as comfortable.

I’ve no more than thought it — the tiny tingle in the small of my back saying somewhere to the east night is rushing toward me — when a great horned owl calls from a brushy draw a few hundred yards away. And just like that, the sun is gone.

The western twilight is brief, but the sky so expansive that for a time I see both night and day on opposite horizons. Planets shine, Saturn and Jupiter, and then the first stars peek through the eastern heavens, pinholes on a steely backdrop reminding me that it’s easier to set up my camera before it’s entirely dark.

Using the augmented reality feature of the PhotoPills app on my smartphone, I check to see where the Milky Way will cross the sky two hours from now. Less than 100 feet in front of me, a west-facing, long-abandoned homestead rises from the prairie, a testament to the hardiness of pioneers and also the harsh times of the Dust Bowl, and I position my tripod to frame it under the arc of our galaxy.

I level my Manfrotto, weighing it down with a large rock pried loose from where I sat earlier, then attach my Skywatcher Star Adventurer equatorial mount, giving it a rough alignment to north with a compass. I’m using its counterweight bar tonight, complete with a nearly-full, 16-ounce water bottle attached for additional weight to balance my Nikon D810 and Sunwayfoto panoramic head.

I’ve found – through trial and error – that proper balance between my camera and counterweight yields markedly better results while this portable mount “tracks” the stars through their nightly journey across the sky. Close to the 45th parallel here, the half-way point between the equator and North Pole, I adjust the mount’s wedge base for this latitude, tipping it skyward toward where Polaris, the north star, will soon be visible, then level my panorama head.

Originally developed for keeping celestial objects in the viewfinders of telescopes while our Earth spins, motorized equatorial mounts now allow photographers to capture the night skies at longer exposure times and lower ISOs without seeing the stars “trail.” With longer shutter times, details otherwise unseen can be extracted from the photos.

I’m shooting with Sigma’s 35mm art lens in portrait orientation tonight, and, turning on my camera and placing it in live view, I swivel it toward a bright star in the eastern sky. In manual focus, I zoom in on the star, watching it grow in size on my LCD screen, adjusting the Sigma’s focus by hand until it is a tiny, perfectly round dot. I’ve found this a more accurate way to gain true infinity focus than by using my camera’s autofocus.

By the time I’m finished, I can see Polaris and, looking through the polar scope of my Star Adventurer, adjust my mount to place it inside the reticle of the scope, aligning my mount’s axis to the pole. I’ll make further adjustments later, closer to the time I’m going to begin shooting, but it’s easier for me to get an initial alignment before it’s pitch dark. I attach my Promote remote control intervalometer to my Nikon, using both cables to allow mirror-up exposing, then return to my rocky seat and wait.

Inside the homestead, I hear the scrape of claws on weathered boards and I smile. I suspect what’s coming, and hold as still as I can while a group of raccoons makes their exit right out a first-story window. I watch the silhouettes of a mother and four kits drop to the ground and file off toward a shelterbelt of Russian olive trees in the distance.

I’ve never looked at these Western homesteads, the few still standing across this semi-arid landscape, without pangs of sadness. They were homes – built by hand to raise families in – abandoned when much of the topsoil here blew away during the 1920s. Some still have dishes in kitchen cabinets, glass bottles with yellowed, peeling labels under the sink, and furniture covered with pigeon and raccoon droppings exactly where it stood when its owners walked away with whatever they could carry.

Today, these houses stand like ghost ships on the prairie, each year a few more succumbing to winter snows, and it’s comforting to me somehow to see that this particular one now houses another family. I watch the raccoons shuffle away into tall grass where better farming practices have ensured more stable topsoil.

A train whistle sounds twice on the edge of earshot, and then it is silent, save the chirp of nearby crickets. I’ve always loved the night sky I think to myself as a satellite passes directly overhead. Photographing it is a solitary experience for me, but I feel a universal connection to everyone who, throughout time, has looked up at night and wondered the same things that I do now: how far does it go on, what exactly is up there, and is there anywhere, millions of light years away, where someone else — either a lot or a little like myself — looks in this direction?

Glancing toward my camera, I think about all we’ve learned regarding space in the centuries after Galileo’s observations. It’s fascinating, but part of me hopes that we’ll never learn it all. I hope we don’t unravel every mystery and that a photographer a few hundred years from now can look upward feeling that, as I do, there’s a little unknown. A little something magical about the universe.

Time moves in one direction, and soon even the western horizon is completely dark. With another app, this time Polar Scope Align Pro, I check exactly where to position Polaris inside the reticle of my polar scope at this time of night. I’ve used Velcro to secure the Star Adventurer’s polar scope illuminator to the counterweight bar in line with the scope, and with its red light shining dimly, I make the final, fine adjustments to my mount’s latitude and longitude, placing Polaris in the right spot.

I turn on the mount’s power, in sidereal speed, and, after waiting a couple of minutes for any backlash to resolve itself, take a test shot using my Promote. Mirror up, ISO 1250, f4, custom white balance of 4850 Kelvin, 2-minute exposure. Reviewing the picture after I hear my shutter close, the stars look nice and round, a sure sign of proper tracking, and I move my camera 15 degrees on its panoramic head and take another picture. I repeat this 10 more times, reviewing each photo, spanning the sky from south to north to capture the entire arc of the Milky Way. In a little over half an hour, I’ve got a dozen pictures that I’m happy with and the waiting game begins again.

Using an equatorial mount allows great imaging of the sky, but since the camera is moving during the exposures, any terrestrial objects appear slightly blurred. Tonight, I’ll wait for the moon to rise and then take the same series of 12 photos from the same location but with my mount turned off in order to yield a sharper foreground.

Waiting, alone in the dark, I think about some of the places I’ve been over the past couple of years to shoot at night. I’ve done star trails at 9,000 feet on the Rocky Mountain Front south of Glacier National Park, worn myself to the point of physical exhaustion carrying my gear into high-elevation mountain lakes to capture the Milky Way and pieces of its reflection in still water, seen where a young black bear walked tight circles in fresh snow around my tripod during an all-night April star trails shoot while I slept less than a hundred yards away, and once while reviewing photos from a fall star trails session found the blurred profile of a mule deer doe staring at my camera, all pictures afterward unusable because she had licked the lens.

I’ve had banks of clouds roll in – after a forecast of nothing but clear skies, forgotten to change the batteries in my equatorial mount on more than one occasion, once after walking more than five miles, and spent several sleepless nights in the dead of Montana’s winter hoping that the chemical hand warmers I had rubberbanded all over my camera provided sufficient heat to keep frost off my lens and its shutter opening and closing all night.

What do I get in return I think as the moon begins to show above the horizon? Unexpected light shows of the aurora borealis, soft air glow invisible to the human eye that sometimes lends a green cast to black skies, plenty of hours alone in beautiful places, and a chance to show the world my interpretation of a midnight moment frozen in time. It’s a blending of art and photography, I think as the moon inches up the sky. A chance to use a photograph as the basis for creation, something that throughout my life I’ve been as drawn to as the wild places I go with my camera.

Even the crickets are quiet now when the moon finally reaches the point I need it to light my foreground properly. I leave my ISO and f-stop the same on my camera, but this time take 40-second, untracked exposures back across the path I traced earlier in the evening. Because my camera and tripod never moved, aligning the two panoramas once stitched – tracked and untracked – is a relatively easy task in post-processing. One sharp sky, one sharp foreground, one photo that shows what I saw.

People often say to me, pointing at one of my photos, “When I look at the Milky Way it doesn’t look like that to me.” Sometimes I will go into detail about the sensitivity of a camera’s sensor, the ability to adjust shadow and light in post-processing, and a camera’s ability to “see” colors that we cannot. But other times I’ll simply shrug, and with something of a smile say, “Well, it does to me.”

Gear/Software Details

My Milky Way gear:

  • Nikon D810 camera
  • Sigma 35mm Art Lens
  • Promote remote control
  • Sky Watcher Star Adventurer equatorial mount
  • Manfrotto 190cxpro4 tripod
  • Sunwayfoto Pano-1 panoramic head
  • Sunwayfoto FB series ballhead

Images processed in Adobe Lightroom and stitched in PTGUI

My star trails gear:

  • Nikon D810 camera
  • Tamron 15-30mm f2.8 lens
  • Promote remote control
  • Manfrotto 190cxpro4 tripod
  • Sunwayfoto FB series ballhead

Images processed in Adobe Lightroom and Photoshop


About the author: Jake Mosher grew up in Northern Vermont and has lived in Montana for 23 years. A published novelist, he has worked as a logger, miner, big-game guide, substitute school teacher, prize-fighter and explosives engineer. In September 2017, Jake walked away from corporate America to pursue his photography full-time. He believes that the world, especially off the beaten path, is still a wonderful thing to see. He has won awards from the Smithsonian, National Wildlife Federation, and several international photo contests. Recently, his star trails photo, Holding Due North (shown at the top of this article), was shortlisted for the 2018 Insight Investment Astronomy Photographer of the Year award, the world’s largest night skies competition. You can find more of his work on his website.



from PetaPixel https://petapixel.com/2018/07/27/the-time-between-a-look-through-the-eyes-of-an-astrophotographer/

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