Circling Stars over Pyramid Mountain


The previous post showcased one image taken last Saturday night at Patricia Lake. This is a composite of 98 such frames, producing an image of stars circling the sky.

This is the motion of the northern sky over 75 minutes, as the Big Dipper and other circumpolar stars arc around the celestial pole, just off camera here. A few faint meteors streak at left. And the makings of an aurora appears at right.

Each exposure was 45 seconds long. I used a Photoshop Action to automatically select each frame in turn and stack it on top of the previous image, then change the blend mode to Lighten and flatten the layers. The end result of the computer crunching away is an image that recreates what we used to achieve with film, by stopping down the lens and exposing a slow ISO film for an hour or more onto one frame.

I last shot this same scene a decade ago with just that technique and Fuji Velvia film, a favourite of mine back then for star trails. But these days shooting multiple short exposures digitally provides the advantage of also netting a folder-full of images suitable for a time-lapse movie, something we could never do with film cameras, unless they were modified movie cameras. I like DSLRs better.

— Alan, August 1, 2012 / © 2012 Alan Dyer

The Big Dipper Over Pyramid Mountain


 

Pyramid Mountain is Jasper’s iconic peak dominating the skyline of the mountain town in Alberta. The mountain and its foreground lakes are ideally placed for nightscapes of the northern sky.

I took this shot Saturday night, July 28, from the shore of Patricia Lake, one of several that dot the benchlands south of Pyramid Mountain. Small lakes like Patricia have the benefit of often being calm and reflective. Here the stars of the Big Dipper and Ursa Major swing over top of Pyramid Mountain, in the blue moonlit sky. A few well-placed clouds add a welcome perspective. This is one frame of 150 or so in a time-lapse sequence, and that will eventually become a star trail composite as well. But this single frame stands well all on its own.

The last time I was here shooting this same scene I was using Ektachrome and Fujichrome film (each had its unique characteristics, though just what I can’t recall!). That was more than a decade ago. This digital shot with the Canon 7D looks far better than what I got back then.

— Alan, July 30, 2012 / © 2012 Alan Dyer