Monthly Archives: September 2007

Trawler on Tomales Bay

Julian and I spent a fun afternoon yesterday, hiking Steep Ravine and the Millerton Point trail in Tomales Bay. But it didn’t seem like a great day for photography, although we did get to examine a bull up close, and study a grotesque half-eaten deer carcass. What fun!

In Marshall, we wandered around the old boatyard, with wrecks of boats up on blocks, and then shared a chowder and oyster dinner at Tony’s. The food wasn’t much to write home about, but the view of Tomales Bay, Point Reyes, and the Ann Marie (the trawler shown in the photo) were great.

As the sun set, I tried a variety of shutter speed and aperture combinations, taking care to underexpose relative to my light readings because meter readings into the sun have a tendency to overexpose. This exposure caught a wild prismatic effect from the sun’s rays.

[105mm, 157.5mm in 35mm equivalent terms, 1/15 of a second at f/32 and ISO 100, tripod mounted.]

Posted in Landscape, Photography, Point Reyes

Iris (the Wave)

This is a Trader Joe’s iris. I used a spray bottle on the flower and lit it from below and behind. Photographed extremely close with a macro telephoto.

[200mm f/4 macro, 300mm in 35mm equivalent terms, 36mm extension tube, 10 seconds @ f/40 and ISO, tripod mounted.]

Related images: Iris, Iris Tongue, Winged Iris, Enough with the Irises!

Posted in Flowers, Photography

Mount Tamalpais Sunset

As I watched the clouds swirl through the Golden Gate, I turned and saw the setting sun beside Mount Tamalpais. This time the sun wasn’t entirely blown out.

[600mm in 35mm equivalent terms, 1/20 of a second and f/32 at ISO 100, tripod mounted.]

Some of my related photos of Mt Tamalpais: Mt Tamalpais from Euclid Avenue, Mt Tamalpais from Diablo, Tamalpais from Mission Peak, Fog Rolling in Across the Bay. As you can see, I like Mt Tam a lot!

Posted in Landscape, Photography, San Francisco Area

Blowing in the Golden Gate

When the clouds blow in the Golden Gate (which is often) and when there’s also a blue sky over the Bay (which is sometimes), then there will be a spectacular show at sunset.

To witness yesterday’s show, I started at the Inspiration Point parking lot at about 5PM and hiked to Wildcat Peak. I had a book with me, and read for a while until the performance started to move quickly. Within minutes after this shot, the sun had set and the Golden Gate was hidden in an inpenetrable layer of fog.

[130mm, 195mm in 35mm equivalent terms, 1/320 of a second at f/9 and ISO 100, handheld.]

Posted in Landscape, Photography, San Francisco Area


This is a reflection of a white iceberg rose bud, photographed on a mirror. I used a spray bottle to make the water drops, and lit the reflection with natural afternoon sunlight.

[85mm PC Micro-Nikkor, 127.5mm in 35mm equivalent terms, 2 seconds at f/51 and ISO 100.]

Posted in Photography, Water Drops

Point Reyes Sunset

What’s a photographer to do? With the sun setting along the coast, however you expose the image the sun is going to blow out. True, in real life the sun blows out when you are looking at it with your eyes as well, and most people therefore practice not looking directly at the sun, even when it is setting. But the naked eye doesn’t perceive the unattractive sharp gradation of color, looking like a solid line, from the sunset sky to the white area of the blown-out sun. Any reasonable exposure for the oceanscape does exactly this awful sharp gradation when processed by a digital sensor.

I don’t really think there’s much choice with this one. You’re not going to salvage it with HDR or multiprocessed RAW, the exposure difference between the sun and cliffs in shadow is too great. So your only move is to expose for the ocean and shore, and let the sun go hang.

I think the photo pretty much works anyhow, and I like a couple of small details, like the bird flying in the sunlight and the small yellow flower on the lower right.

[12-24mm zoom lens at 24mm, 36mm in 35mm terms, 1/200 of a second at f/7.1 and ISO 100, handheld.]

Posted in Landscape, Photography, Point Reyes

Water Marbles

I first blogged this photo in June of 2006 in a supporting role in a story called More Drops. I think “Water Marbles” deserves a story of its own.

Posted in Photography, Water Drops

Core of the Anemone

When I posted yesterday’s photo of a pink anemone, I realized I had never blogged this white anemone core from a year ago, and I really like it (so here it is).

Related image: Jet Engine.

Posted in Flowers, Photography


Anemones are members of the ranunculus family, and related to the buttercup. Taking a break from my task of working on my new book, Digital Light and Exposure, I couldn’t resist cutting some flowers from the garden, including dahlias and this anemone. With the cut flowers in water, I just had to photograph them. I used natural light in my studio, and classic high depth-of-field macro technique.

Related images: White Anemone, Anemone Japonica.

[85mm macro lens (127.5mm in 35mm terms, 36mm extension tube, 20 seconds at f/64 and ISO 100, tripod mounted.]

Anemones are said to be symbolic of memory, although I think this one looks more like an angel with wings and a burning core than a memory bank. In any case, the flower is apt for the day, 9/11. Few of us will forget the anniversary of an event that transfigured our world, and changed it for the worse. Here’s one of my photos, scanned from a slide, of the New York skyline before the Trade Towers came down.

Posted in Flowers, Photography

Licensing My Photos

I’ve been getting an average of three or four inquiries a week about licensing my photos. This is a good thing. It’s fun to interact with people who are enthusiastic about my work (and, hey, even willing to pay to use it!). These inquiries are coming almost entirely from my web presence in Photoblog 2.0 and on Flickr.

The size of these licensing deals has ranged from fairly small (for example, an image to be used by an alternative medical practioner in New Zealand for a logo) to book covers and global advertising campaigns. The international reach of the Internet, as shown by this commercial interest in my digital photo library, thrills me.

The volume of these licensing inquiries has been getting to the point that I felt it was time to create an information page about licensing Harold Davis photos. Of course, my hope is that by putting information about how to find my photos and license them in one place I will spur additional interest.

As I put together the licensing information page, I was really struck by what a “mash-up” my online presence is: I handcode web pages in PHP, I use WordPress to manage my blogging, and I use Flickr as my web image repository. I’ve also “out sourced” my comment management to Flickr, and I use Flickr’s taxonomic categorization tools and tagged searching mechanisms. For full-text search, I’ve got a Google search box tied into my blog and content sites. Paypal lets me easily accept international payment for web usages that would otherwise not really be practical.

I know it’s been said before, but what a tangled web we weave…

Carobrotus Edulis Drop

View this image larger. Read the back story featuring this image.

Posted in Photography


This is the most western point of the Point Reyes peninsula, and therefore the most western spit of land in the continental United States. If you could see around the corner in the photo, you’d find the Point Reyes lighthouse.

I took the photo from along the Chimney Rock trail a few days ago. The sunset was blood red because of particles from a forest fire a couple of hundred miles to the north.

[105mm lens, 157.5mm in 35mm equivalent terms, 1/125 of a second at f/5.6 and ISO 100, tripod mounted.]

Posted in Landscape, Photography, Point Reyes

Star Trails

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.

Posted in Digital Night, Landscape, Photography

Using the Exposure Equation

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.

More Night Music

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.

Posted in Digital Night, Landscape, Photography

Morning Pink

As the sun rose, the light on these tiny water drops along a petal on a dahlia flower grew translucent. The water drops glowed with pink, and as they did, so did I.

Related images: Morning Star, Gerbera Drop, Camellia Decolletage, Dahlia Drops.

[200mm f/4 macro, 300mm in 35mm equivalent terms, 36mm extension tube, +4 diopter close-up filter, 1/6 of a second at f/45 and ISO 100, tripod mounted.]

Posted in Flowers, Photography, Water Drops

Morning Star

In the morning, chaos of kids and family permitting, I like to photograph in the garden. The sun was rising, there was little wind, and water was just sliding off the dahlia drop. I used an improvised reflector–the white handkerchief I keep in my camera kit–to send some light into the dahlia bud, otherwise dark against the background.

Related images: Beneath the Dahlia, My Favorite Worlds, Navigation and a Water Drop.

[200mm f/4 macro, 300mm in 35mm equivalent terms, 36mm extension tube, +4 diopter close-up filter, 1/8 of a second at f/32 and ISO 100, tripod mounted.]

Posted in Flowers, Photography, Water Drops