Star Trail Reflections at Bow Lake, Banff

It’s rare to get such a clear night in the mountains, but last weekend, July 6-7, provided a couple of ideal nights.

This image combines about 180 exposures, each 45 seconds long, stacked to create a single image of long star trails setting into the west behind Bow Glacier in Banff. The result records the sky’s motion over nearly two and a half hours. Running at right angles across the descending stars are vertical streaks from a bright meteor (left) and a satellite (top, centre).

Light from the rising waning Moon provides the illumination.

— Alan, July 16, 2012 / © 2012 Alan Dyer

Circling Star Trails in the Rockies

Let the camera shoot for a few hours and this is what you get: stars circling the sky, turning into concentric paths around the North Star.

For this image I stacked 230 short exposures, each 50 seconds long, taken over about 4 hours time on July 7/8. My previous blog entry is one of those individual frames. But in this composite, the stars become trails rotating about the pole of the sky, near Polaris, the North Star, here over Num-Ti-Jah Lodge at Bow Lake in Banff. Moonlight provides the illumination and turns the sky blue, just as in daytime, only much dimmer. But the long exposures bring out the colours and make the scene look like daylight, because the light of the Moon is daylight, just reflected first off the Moon’s neutral grey face.

The same frames used to make this still frame composite can also be used to make a time-lapse movie of the circumpolar stars turning.

— Alan, July 14, 2012 / © 2012 Alan Dyer

Trails of Orion Over Fairview

I love the lighting in this shot from Saturday night. I took this by standing out on Lake Louise, from a spot you couldn’t be in summer without getting wet!

Moonlight grazes the east and north slopes of Mount Fairview, while spill from a skating rink flood lamp lights the trees. The sky is deep blue from moonlight making this look like a day scene.

But this is actually a 4-minute exposure, purposely long to allow the stars of Orion and the bright star Sirius at left to trail across the heavens over Fairview.

Unlike most nightscape shots, of necessity taken at high ISO speeds to grab lots of light in a short exposure, I took this shot at ISO 100. Even with the blog’s low resolution images, I think you can see the difference here – this slow-speed shot looks richer and smoother, lacking the fine noise that is inevitable in high ISO shots. It’s just like using slow speed film – in the old days I’d always carry two types of film for trips like this: slow Velvia 50 for long star trail shots, and fast Fuji or Ektachrome 400 for the untrailed nightscapes. I always loved the Velvia shots – they were indeed like smooth velvet.

Now with digital cameras you can switch settings as you like. And see the results instantly. How did we ever manage to get any results with film?

— Alan, February 6, 2012 / © 2012 Alan Dyer

Sacred Site: The Movie

Here’s my time-lapse sequence of the hoodoos at Writing-on-Stone Park lighting up as the Moon rises and the Milky Way sets.

The sky starts off dark but lights up as the waning Moon, off frame behind the camera, rises and lights up the foreground and sky. The sequence ends as the sky brightens with the onset of dawn.

Waning moons are great nights for this type of shooting as the changing lighting produces dramatic effects as the landscape lights up at moonrise. The problem is, the Moon doesn’t rise till very late, making for a long night of shooting.

I assembled this sequence from 290 frames, each a 60-second exposure, taken at 1-second intervals over about 4 hours. The camera was the Canon 7D and the lens the 10-22mm Canon EF-S zoom at 10mm. I also shot a matching sequence simultaneously with the 8mm fish-eye and Canon 5D MkII camera, for an all-sky sequence for planetarium use.

— Alan, July 30, 2011 / Movie © 2011 Alan Dyer

Circling the Sky II

My encounter with the old farmstead near home continued the next night (after the shot featured in the previous blog), under another stunningly clear moonlit sky. Here I let the camera fire away for three and half hours, producing a rather neat juxtaposition of surreal starfield above an abandoned old farmhouse.

For this shot I stacked 660 17-second exposures that were taken in rapid succession at one second intervals. I used the Canon 5D MkII at ISO 800 and Sigma 8mm lens  at f/4.5.

My workflow for an image like this is to…:

1. Use Adobe’s Photo Downloader to download all the images from the camera card into a folder on a local hard drive, then open Adobe Bridge to inspect them. Toss out any junk shots at the beginning and end of the set.

2. Open a representative image in the sequence using Adobe Camera Raw and process it for Colour Correction, Contrast, Noise Reduction, Vibrance, Fill Light (to bring out shadow detail) and Recovery (to recover details in highlights).

3. Then in Bridge, go under Edit: Develop Settings: Copy Camera Raw Settings.

4. Select all the images (Select All) and then Paste Camera Raw Settings. This applies that custom setting to all the images in the sequence in one fell swoop. 600+ images processed in seconds! Sometimes it can take a few iterations to get a good setting that works well through the whole set.

5. Then Select All again in Bridge and go under Tools: Photoshop: Image Processor. This open Photoshop itself and brings up a dialog box that allows you to convert those processed RAW files into other formats (JPGs, TIFFs, etc. in whatever size you want). For this type of single image I convert the RAWs into full resolution TIFFs. While I am at it, I’ll also convert each image into a smaller-sized (1080 pixels high) JPG. The folder of JPGs are for creating an HD-format time-lapse movie from the same set of images. Image Processor can create two sets of images simultaneously from the same RAW master. Very nice.

6. This will take a while as Image Processor dutifully opens up each image one by one and creates a TIFF (and a JPG, too, if you like) from each RAW file in another folder. Go for a very leisurely coffee!

7. Once a folder of finished TIFFs is there, I can use Chris Schur’s Photoshop Action to take each of those images and stack them one by one into a single image. That process can take hours with full-res TIFFs. Start it before you go to bed! Slow, yes, but it’s better than doing it all by hand.

8. The final image can still use touch-ups, to sharpen, alter the brightness and contrast of the sky (frames taken when the sky was still bright with twilight can make the scene look too bright).

It can take a day’s worth of computer crunching to get a final image. But the result is certainly unique.

— Alan, July 20, 2011 / Image © 2011 Alan Dyer

Circling the Sky

It has been an incredible week for imaging. Clear skies and a bright Moon are the tickets to nightscape photography. And in the last week we’ve had clear moonlit nights in abundance.

I’ve taken advantage of the run of great weather to shoot an old farmstead down the road from my house, on several nights. This is a shot from the first night out, on Thursday, July 14. It is a fish-eye lens shot taking in most of the sky, and looking north at the bottom of the frame. The star trails, taken over 2 hours, circle around the North Star (or close to it).

So why is the sky blue? The Full Moon, just out of the frame at top, is illuminating the landscape and sky — and light from the Full Moon is the same colour as light from the Sun (because that’s what moonlight is! — reflected sunlight). It’s just that moonlight is much dimmer. Expose long enough and you get a scene that looks like daylight but has the stars in it.

To create this image I took 400 18-second exposures, taken 1 second apart, using the Canon 5D MkII camera at ISO 800 and the Sigma 8mm lens at f/5. I stacked the images using an automated “action” for Photoshop developed  by astrophotographer Chris Schur. The original frames can also be strung together in sequence to create a time-lapse movie of the sky turning, suitable, in this case, for projection in a full-dome digital planetarium. I’ll post some of those shortly.

But after several nights of shooting till 3 and 4 a.m., and accumulating 100 gigabytes or more of RAW files, it’s time to take a night off and turn in early! At 1 a.m.!

— Alan, July 19, 2011 / Image © 2011 Alan Dyer

Summer Solstice Space Station

We’re currently enjoying a series of nightly (and often twice or thrice nightly) passes of the International Space Station, coinciding with the bright nights of summer solstice.
I took this shot on the night of solstice, June 21, 2011, as the Space Station came directly overhead, flying out of the west then heading off into the east. So we’re looking a little west of north here, toward the bright northern horizon. Pity some light cloud hazed up the sky. The pass began at 11:12 pm so the sky was still quite bright, though even an hour or two later at this time of year the northern horizon is tinged with perpetual twilight glow, at least at my latitude of 51° N.
To create the image I took a series of 100 3-second exposures (as long as the bright sky would allow) taken 1 second apart in rapid-fire fashion with the camera firing automatically with a remote timer. The 1 second gap between exposures creates the gaps in the Space Station trail.
I processed the images in Adobe Camera Raw, and exported them all as TIFFs to their own folder. I then used Chris Schur’s excellent “Star Trails” Photoshop Action to stack all those images into one composite image showing the complete flight of the Space Station across the sky. A little application of Shadows and Highlights helped bring out the foreground and bright sky detail.
I used the Sigma 8mm fisheye lens and Canon 5D Mk II to capture the whole sky, for a still and time-lapse sequence suitable for projection in a full-dome video planetarium … because the neat thing about this method is that the same set of images can be strung together sequentially (using Photoshop Extended’s Movie function) into a time-lapse movie of the pass, showing cloud and star motion as well as the ISS passage. The same techniques work for star trails, as indeed you can see here with the stars of the northern sky (Big Dipper at left and Cassiopeia at right) trailing around the North Star.
— Alan, June 22, 2011 / Image © 2011 Alan Dyer