September 4, 2016 – The Amazing Sky

What a night this was – perfect skies over an iconic location in the Rockies. And an aurora to top it off!

On August 31 I took advantage of a rare clear night in the forecast and headed to Banff and Moraine Lake for a night of shooting. The goal was to shoot a time-lapse and stills of the Milky Way over the lake.

The handy planning app, The Photographer’s Ephemeris, showed me (as below) that the Milky Way and galactic centre (the large circles) would be ideally placed over the end of the lake as astronomical twilight ended at 10:30 p.m. I began the shoot at 10 p.m. as the sky still had some twilight blue in it.

I planned to shoot 600 frames for a time-lapse. From those I would extract select frames to create a still image. The result is below.

Milky Way over Moraine Lake — This is looking southwest with the images taken about 11:15 pm on August 31, 2016.The ground is illuminated by a mix of starlight, lights from the Moraine Lake Lodge, and from a display of aurora brightening behind the camera to the north. The starclouds of Scutum and Sagittarius are just above the peaks of the Valley of Ten Peaks. This is a stack of 16 images for the ground, mean combined to smooth noise, and one exposure for the sky, untracked, all 15 seconds at f/2 with the Sigma 20mm Art lens and Nikon D750 at ISO 6400. The frames are part of a 450-frame time-lapse.

As the caption explains, the still is a composite of one exposure for the sky and 16 in succession for the ground, averaged together in a technique to smooth noise. The camera wasn’t tracking the sky, so stacking sky images isn’t feasible, as much as I might like to have the lower noise there, too. (There are programs that attempt to align and stack the moving sky but I’ve never found they work well.)

About midnight, the Valley of Ten Peaks around the lake began to light up. An aurora was getting active in the opposite direction, to the north. With 450 frames shot, I stopped the Milky Way time-lapse and turned the camera the other way. (I was lazy and hadn’t hefted a second camera and tripod up the steep hill to the viewpoint.)

The lead-image panorama is the first result, showing the sweeping arc of Northern Lights over Desolation Valley.

Aurora over Desolation Valley #2 — The Northern Lights in a fine Level 4 to 5 display over Desolation Valley at Moraine Lake, Banff National Park, on the night of August 31/Sept 1. This is one frame from a 450-frame time-lapse with the aurora at its best. This is a 2-second exposure at f/2 with the Sigma 20mm Art lens and Nikon D750 at ISO 5000.

Still images shot, I began a time-lapse of the Lights, grabbing another 450 frames, this time using just 2-second exposures at f/1.6 for a rapid cadence time-lapse to help freeze the motion of the curtains.

The final movies and stills are in a music video here:

I ended the night with a parting shot of the Pleiades and the winter stars rising behind the Tower of Babel formation. I last photographed that scene with those same stars in the 1980s using 6×7 film.