Pole Star, photo by Harold Davis. View this image larger.

This is the last of a sequence of twelve photos of the wrecked Point Reyes trawler near Inverness. I took these photos the other night over the course of a couple of hours. The sequence started with The Long and the Short, and included Star Trawler. Like Star Trawler, this last capture in the series is a 1,204 second (20 minute) exposure.

As I was taking this photo, I was interested in the reflection of the boat in the water. I’ll admit I was pretty bored with all the waiting around during the long exposures and the in-camera noise processing, so I augmented the reflection with a little discreet light painting on the hull with my headlamp.

I also angled my camera so that it was facing due north and the Pole Star. The Pole Star, also called Polaris or the North Star, is almost stationary in this photo while all the other stars trail around it. This is because the Pole Star lies nearly in a direct line with the axis of the Earth’s rotation “above” the North Pole.

It has been rudimentary night-time navigation for thousands of years in the nothern hemisphere to determine north using the Pole Star (and is still useful if you are lost in the wilderness at night without a GPS or compass).

To determine north, first find the Big Dipper. Next, locate the “cup” part of the dipper so you can draw a mental line extending from the star Merak and extending beyond the star Dubhe (you’ll find a diagram in the Wikipedia article). The extended line will point at the bright Pole Star (it’s about five times as far from Dubhe as Merak and Dubhe are apart). Draw a line from the Pole Star to the earth, and you’ve fairly accurately found north.

This explains why I was excited when I spotted the Big Dipper pointing to the Pole Star directly above the wreck of the Point Reyes. I was hoping to capture the stars whirling around the single still point of Polaris above the boat.

[Nikon D300, 12-24mm zoom lens at 13mm (19.5mm in 35mm terms), 1,204 seconds at f/22 and ISO 100, tripod mounted.]

Star Trawler 2, photo by Harold Davis. View this image larger.

This is my first, and shortest, exposure of the Point Reyes boat the other night. As I explained in my original story about the star trawler, I was surprised to find the apparently monchromatic moonlight producing such vibrant colors.

The longer exposure was intended to produce star trails, but I like the effect here too: of stars more the way we see them.

The pair of photos illustrates a spread of aperture-shutter speed combinations, both at essentially the same exposure value: from 1,204 seconds at f/22 at the long end to 30 seconds at f/3.5 at the short end. (“Long” and “short” refer to time.) Since depth of field is not an issue in these photos, the contrast is a good illustration of the differing way exposure time treats objects in motion (the stars).

[Nikon D300, 18-200mm VR zoom lens at 18mm (27mm in 35mm terms), 30 seconds at f/3.5 and ISO 100, tripod mounted.]

Star Trawler 1, photo by Harold Davis. View this image larger.

This is a 1,204 second (or about twenty minute) exposure of the wrecked fishing trawler Point Reyes. I’ve photographed this boat before, but never at night.

There was a bright moon in the sky, and as I walked across the mud flats behind the Inverness General Store, my fear was that all that moonlight would detract from the starlight. As I set up my tripod, polka music came faintly from the Czech restaurant in Inverness. Vladimir’s, it seems is still run by 78-year-old Vlad, and according to this review sometimes features live music from the old country, which must have been what I was hearing. Somehow, the music seemed to fit the slightly sad scene of the wrecked boat forever grounded on the mudbank.

As I began running test exposures, it became clear from my review in the LCD that my fears that moonlight would render colors monotonic were misplaced. It’s true that the stars were not as bright in the sky as they would have been on a moonless night. But the moonlight brightly lit the dark mass of the trawler (helped along in this exposure, I confess, with a little judicious light painting with my head lamp). The moonlight also created the reflections in the water in the foreground. If you look closely, you’ll even see reflected star trails.

And the astounding thing was that to my eye the world lit by moonlight was close to monochromatic, but the sensor picked up things with the vivid colors you see here.

For this long exposure, I stopped the lens down to f/22, with the idea of picking up as much star motion as I could.

[Nikon D300, 12-24mm zoom lens at 13mm (19.5mm in 35mm terms), 1,204 seconds at f/22 and ISO 100, tripod mounted.]