Mount Kobau Nightscapes


Big Dipper Down the Road

The pines and sagebrush landscape of the summit of Mount Kobau are illuminated by the light of just the stars and Milky Way.

This collection of images from Monday night, July 28, captures the night sky above and the land below in classic “nightscapes.”

I took all of these with a camera on a static tripod, with no tracking system involved here. All are about 40-second exposures at ISO 3200 to 6400 with a fast 24mm lens at f/2.5 on a Canon 6D.

However, for the image above I composited two exposures: a shorter 40 second shot for the sky and a longer 1 minute 40 second shot for the ground. I used Photoshop’s Quick Selection tool to make a rough selection of the ground, then the Refine Mask and Smart Radius tool to refine the edge to precisely mask the sky separately from the ground, for individual processing.

The top image shows the Big Dipper and a well-timed meteor, at the end of the summit road on Mt. Kobau, near Osoyoos, BC.

Big Dipper & Arcturus from Mt Kobau

This image takes in the Big Dipper at right pointing down to Arcturus at left. I used Photoshop’s Content Aware Fill to neatly eliminate a power pole and wires.

Sagebrush and Stars

Looking southwest reveals the Milky Way above the sagebrush and pine trees. This is a single exposure, with the ground processed with Shadow detail recovery to bring out the starlit ground.

Pleiades Rising Down the Road

This image, taken about 2 a.m., records the Pleiades star cluster rising down the end of the summit road, with Capella at left. It is a dual-exposure composite: 40 seconds for the sky and 1m40s for the ground.

I gave a talk at this year’s Mt. Kobau Star Party on how to shoot these kinds of nightscapes, illustrated with some of these images shot on site the night before. Very nice!

– Alan, July 30, 2014 / © 2014 Alan Dyer

 

The Milky Way at Solstice


Centre of Galaxy on Horizon (June 9, 2013)

The centre of the Galaxy culminates over a starlit landscape on a night near the summer solstice.

This was last weekend, on the same night I took the images of the aurora and noctilucent clouds featured in the previous two blog posts. But toward the end of the shoot, I turned south to capture this scene, of the Milky Way over a grassy prairie field.

The landscape is lit only by starlight and by the glow of twilight and aurora to the north.

In the sky, the constellations of Scorpius and Sagittarius are peaking as high as they get for me in southern Alberta. The red giant star Antares is to the right while the bright star clouds toward the centre of our Galaxy are just left of centre. The sky is not dark because of the glow of perpetual twilight at this time of year near solstice.

Deep sky fans will note that the star cluster M7, the southernmost Messier object, is just clearing the horizon.

Remarkably, this is a mere 15 second exposure, at ISO 1600 but with the 24mm lens wide open at f/1.4. Normally I wouldn’t shoot at that wide an aperture as the images look too distorted at the corners of the frame. But for this shot I used the Canon 60Da camera – its cropped-frame sensor records only the central area of what the lens projects so it crops out the nasty stuff at the corners of the frame that would certainly have been detracting had I used the full-frame camera.

But shooting at f/1.4 allowed even this quickie 15-second shot to grab lots of detail in the Milky Way.

– Alan, June 14, 2013 / © 2013 Alan Dyer