Coming down from Angels Landing in the dark, I paused after the set of switchbacks known as Willy’s Wiggles. Looking back, I saw Angels Landing silhouetted (on the right). I exposed for about twenty minutes, with the camera pointed close to due north (which accounts for the exaggerated circular motion of the star trails).
[18mm in 35mm terms, 1199 seconds at f/4 and ISO 200, tripod mounted.]
Driving into Yosemite on a clear November evening, I stopped at Tunnel View for this 25 minute exposure from the classic Ansel Adams view spot.
With night photos, the color depends on your white balance setting (star light is not sun light). Night photography utterly baffles auto white balance settings, so the best bet is to correct the white balance in post-processing.
After the sun went down, the stars came out. I thought a photo of star trails above a fog bank would be unusual, so I made this three minute exposure.
Then a park ranger came along, and told us we needed to be off the slopes of Mount Tamalpais 15 minutes after sunset. Makes it kind of tough on a night photographer.
Related image: Star Trails.
[24mm in 35mm terms, 180 seconds at f/9 and ISO 100, tripod mounted.]
Note to readers: please bear with me, I’m on a photo trip, and I won’t be posting for a while. Hopefully my work while I’m gone will be worth the wait!
On a memorable evening close to the 2007 summer solstice, I climbed down from the top of Lembert Dome as the sun set. On my way to the Olmsted Point area to photograph star trails over Half Dome, I stopped to photograph the shores of Lake Tenaya by starlight. This was a 3 1/2 minute exposure with the ISO boosted to 640.
The photo below shows the view of Lake Tenaya from more-or-less the same spot in daylight hours.
Besides ambient starlight, you can see a couple of exogenous light sources in this photo: car headlights in the distance on Route 120, and the light trail of a satellite traversing up the right-hand side of the sky.
[24mm in 35mm terms, 210 seconds at f/4 and ISO 640, tripod mounted.]
View this image larger.
From the cliffs above Sausalito, in one direction the Golden Gate Bridge in alignment, and across the bay, San Francisco. In the other direction, Sausalito & Belvedere Island with lights, terraces, and pleasure craft. This is a night scene in the city, but looked at abstractly it could be something like a blow-up of an amoeba, or?
Related image: Sausalito at Twilight.
On a full moon night, I photographed from Kirby Cove. The moon was rising from behind and below the Golden Gate Bridge. As the moon rose, it seemed to be in position to “roll” along the suspension lines.
I exposed so that some of the background would be apparent, causing the moon itself to blow out with overexposure (this is seen more often with the sun than the moon). When I post-processed, I decided to leave the high contrast effect intact.
[600mm in 35mm terms, 2 seconds at f/5.6 and ISO 100, tripod mounted.]
Heading home along the night trail, I stopped to take this photo of a night beach on Point Reyes.
[27mm in 35mm terms, 180 seconds at f/5.6 and ISO 400, tripod mounted.]
On the night trail home from Sculptured Beach, I stopped to take a photo near where the Coastal Trail meets the Woodward Valley Trail. You can see the broad sweep of Drakes Bay and the outer Point Reyes peninsula in the background, also star trails and the lighthouse in the distance. With a three minute exposure at f/3.5 and ISO 400, this night scene appears as bright as day.
Related site: Digital Night.
The Waldo Tunnel guards the northern approach to the Golden Gate Bridge. From the mound hundreds of feet above the tunnel roof, lights of San Francisco spread out before me. It was not quite a digital night situation because of the strong ambient light from the city. The lighting on the roadways approaching the bridge cast a fiery glow, reminding me of this earlier image from Slacker Ridge (to the southwest of the current location, but in the fog).
For information about this location, see my story Alignment.
[33mm in 35mm terms, 180 seconds at f/9 and ISO 100, tripod mounted.]
The fishing trawler was returning to port through the Golden Gate. As the boat headed for the channel of moonlight, I realized that a long time exposure just wouldn’t do. I wanted to capture the trawler in the moonlight, not an abstraction of the boat rendered into colored lines of motion over the exposure duration. So I boosted the ISO to 1,000 and opened the shutter for a brief (for night) period of 2/5 of a second.
View this image larger.
[300mm in 35mm equivalent terms, 2/5 of a second at f/5.6 and ISO 1000, selectively post-processed for noise, tripod mounted.]
This photo shows the Marin Headlands landscape just after dark from the Point Bonita Lighthouse. Mark and I were lucky enough to be able to photograph from the lighthouse after sunset last week on a docent-led photo tour. The shadow on the massive cliff is of the walkway over to the lighthouse, and the lights in the distance are Muir Beach.
I’m using this photo to mark roughly my 1000th post on Photoblog 2.0. Literally, this is post number 1004, but I have deleted a few posts now and then. So, roughly, a millenium of stories and photos. And, by the way, my photostream on Flickr just passed the quarter of million views mark (yes, that is 250,000!). So, welcome the new millenium.
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In the beginning: Who put these ducks adrift in a bathtub so wide? Read more. |
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Post 101: I’m continuing to play with my marbles… Read more. |
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Post 201: Should I buy a Canon or a Nikon? Read more. |
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Post 300: Julian and I went over to Indian Rock for sunset… Read more. |
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Post 400: I’m pleased to present this triptych of poppy photos… Read more. |
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Post 500: Some people have bird baths, plastic gnomes, wishing wells, or pink flamingos in their garden… Read more. |
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Post 598: I’ve been reading Dan Margulis’s masterful Photoshop LAB Color: The Canyon Conundrum and Other Adventures in the Most Powerful Colorspace… Read more. |
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Post 700: The patterns in this image of the forest in snow don’t make for a grand statement… Read more. |
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Post 800: This is a photo of early morning in Yosemite Valley from Leidig Meadow… Read more. |
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Post 900: A great bank of fog has covered the Bay area, so it’s a little hard to remember that this past week was summer… Read more. |
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Post 1001: I’ve never blogged this photogram of a Peruvian Lily… Read more. |
From Point Bonita, the Golden Gate and the city twinkled around the bend. What was the mystery boat in the moonlight? A fishing trawler perhaps, or a coast guard ship waiting…lights of a farmhouse (actually, Golden Gate National Recreation Area employee housing) look warm and inviting, surprisingly rural so close to San Francisco.
[30mm in 35mm equivalent terms, 10 seconds at f/5 and ISO 100, tripod mounted.]
I wanted to properly expose an image that showed long star trails without the moon. I set my timer to delay the exposure, which started at about 2:30AM and went on for 6,554 seconds (or close to 1 hour and 50 minutes) at f/5.6 and ISO 100. Besides the star trails, you can see fog on the ocean and the early light of pre-dawn.
There are a number of problems to solve in night photography, including seeing what you are doing, not falling off a cliff in the dark, running out of juice in your batteries, and dealing with digital noise. The payoff, if you can all manage this, includes wonderful star trails, night music, and the digital landscape of the night as human eyes have never seen it.
Like any other photograph, a photograph of the night needs to be exposed properly. To digress slightly, a proper exposure is not merely measurement of of the average amount of light falling on your subject, and setting the camera accordingly. Proper exposure involves creative assessment of whether a photo needs to be exposed for portions of the subject, and possible further adjustments to make the image lighter or darker.
The good news is that digital photography usually gives us instant feedback as to whether our exposure was at least in the right ballpark (just review the photo in your LCD).
The bad news is you often can’t review a long night exposure in real time because, well, the exposure is too long. Take a 90 minute exposure like the one below that shows the moon dropping into the Pacific Ocean. In addition to the 90 minute exposure time, it took about 45 minutes for my Nikon D200’s processor to chug through the image and save it. Even if you want to stay up all night (and I didn’t, I was fast asleep when this photo was taken), you get one crack a night. Before I could have made another exposure, the moon would have been long set and dawn would have been approaching.
Here’s where the exposure equation comes to the rescue.
View this image larger.
The exposure equation says that any given exposure (remember, an exposure controls the appearance of your photo, and is not merely a measurement of light) is set using three variables: shutter speed, f-stop (aperture), and sensitivity (ISO). To maintain a constant exposure, if you slow the shutter speed down to let in more light into your camera, you must compensate by selecting a smaller f-stop to allow less light into the camera (or by selecting a lower ISO).
Conversely, once again to hold an exposure constant, if you speed up the shutter speed, which lets less light into the camera, then you must compensate to allow more light into the camera by choosing a more open aperture setting (or by boosting the ISO).
In practice, you can use the exposure equation to run tests for long exposures like the 90 minute night exposure shown above. The method is to use a short as shutter speed as possible, with the camera lens wide open. You can then play with the ISO to get an exposure you like. A back-of-the envelope calculation will tell you how to set the camera for the long exposure.
Here’s how this method worked to find the exposure settings for image above. I set the camera to make 30 second exposures at f/4. I then tried exposures at various ISO values. The image below came out fairly well at ISO 640 (I tried ISO settings between 200 and 1,000).
Now I had my baseline. I knew two of the three variables in the exposure equation for the long-exposure photo: I wanted to take it at ISO 100 to reduce noise as much as possible, and I wanted a 90 minute exposure (the length of time from the beginning of the exposure to a few minutes after moonset). The missing variable was the f-stop (aperture), and I could use my test exposure and the exposure equation to find this value.
To go from 30 seconds to 90 minutes meant I would be letting in 180 times as much light (without other adjustments). To go down in sensitivity from ISO 640 to ISO 100 meant reducing the amount of light by 6.4 (OK, call it 6 to make calculations in the dark easier). Divide 180 by 6 and you can easily see that the aperture I selected should let in roughly 1/30 of the light as f/4.
The aperture in a lens is approximately circular, and the designation of aperture openings (f-stops) is on a logarthmic scale. Starting with f/4, each of these apertures lets in roughly half the light of the preceding aperture: f/4, f/5.6, f/8, f/11, f/16, f/22. So, 1/2 * 1/2 * 1/2 * 1/2 * 1/2 equals 1/32, which is why I chose f/22 for my exposure (at 5393 seconds and ISO 100). Since I thought the test exposure was a little too bright (the reflection of the moonlight below shows some highlight blowout), I wasn’t unhappy to cut the exposure by a little bit extra (by dividing by 6 rather than 6.4, and by cutting the aperture by 1/32 rather than my estimated 1/30).
View this image larger.
Related story: Night Music, Exposing the Digital Night.
Related site: Digital Night by Harold Davis.
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On our Sea Ranch vacation we had a number of clear nights without fog. I took advantage of these nights to photograph the night sky over the Pacific. Each clear night until we moved to another house I set up a long time exposure. We moved because of a scorpion in the house, a broken dishwasher, and raccoons in the trash: another story. But the next house was in a Sea Ranch suburb without the same unbroken view of the night sky.
My modus operandi on clear nights was to set the camera up just below the hot tub. I used my timer to set a delay of some hours, and used the camera’s Bulb setting to open the shutter for a number of hours. After the hot tub, Phyllis and I went to bed and I got up and examined my results in the morning. I used an AC power supply plugged into an extension cord, because even one of these exposures takes more juice than my D200 has in a battery.
This is a 6,554 second exposure, or close to two hours, starting at about 12:30AM and ending around 2:30AM. The bright, comet-like light is the setting moon going down into the ocean while stars wheel round above. You can see lens artifacts in the image caused by the comparative brightness of the setting moon during this long time exposure.
When I post-processed this image, I intentionally left noise in the sky. It seems to me a better effect than making the star trails seem too smooth. After all, noise is the digital era’s version of grain: like grain it can be used for aesthetic purposes.
Related site: Digital Night by Harold Davis.
[16mm, 24mm in 35mm equivalent terms, 6,554 seconds at f/16 and ISO 100, tripod mounted.]
