Monthly Archives: October 2008

Emperor Julian

Emperor Julian

Emperor Julian, photo by Harold Davis.

In this photo Emperor Julian is shown with his brothers Indiana Skywalker (a/k/a the Alien Monster, on the right) and the deceptively innocent-looking Holy Terror (stage left).

Worth noting: In the grand tradition of Scarlett O’Hara and Carol Burnett, Phyllis fashioned the Emperor Julian’s toga from old curtains. The laurel wreath was likewise handcrafted using an old coat hanger and leaves from our garden.

Red and Purple Gladiola

Red and Purple Gladiola

Red and Purple Gladiola, photo by Harold Davis. View this image larger.

Briefly noted: I carefully positioned the gladiola stems on a light box. I photographed almost straight down, but at a slight angle, using a telephoto macro. I made a wide range of exposures so I could be sure of capturing both the transparent effect and the entire possible dynamic range of the subject.

In Photoshop, I placed the different exposures in a layer stack, and used masking to control the color saturation. Then I inverted the white background and used my patent pending cross-channel blending system to bring out the colors (only kidding about the patent!).

[Nikon D300, Zeiss 100mm f/2.8 macro lens, five exposures between one and ten seconds combined in Photoshop, each exposure at f/22 and ISO 100, tripod mounted.]

Alien Monster

Alien Monster

Alien Monster, photo by Harold Davis.

Nicky went to his school Halloween parade dressed as an “alien monster” in huge orange sunglasses, red spiked hair, and his mom’s orange vest. Black finger nails—Phyllis painted all three boys—are not apparent in this photo. Here’s a photo of Nicky from a Halloween d’année passé (Nicky is the little pirate on the left).

Stacking Star Trails: Tips & Techniques

Edge of Night

Edge of Night, photo by Harold Davis. View this image larger.

“Holy Stacking Star Trails, Batman!”…As many of you know, I’ve been shooting and then stacking star trails lately. The idea is to take numerous “shorter” exposures that include the night sky, rather than one longer exposure. The shorter exposures are then composited together (they are “stacked” one on top of other).

A set of exposures that can be composited together to create an interesting star trail image is not always the easiest thing to achieve. But the technique does have some potential benefits compared to a single very long exposure:

  • A stacked composite image is less noisy than a single very long exposure.
  • The effective exposure time possible with a single battery is extended by segmenting the exposure (see my comment about long exposure noise reduction below).
  • Single captures that contain disturbing elements such as airplane trails or light from the photographer’s headlamp can be eliminated from the stack if desired. In other words, stacking gives you granular control over the time slices.

The most important thing when attempting to photograph star trails for stacking, of course, is to find the right view. Ideally, the scene should be free of ambient light—this goes for moonlight, city light pollution, and car headlights. Since my star trail images include a landscape in the foreground, I like to find a location in which the general scene (and not only the night sky) is interesting.

To get the effect of circular star trails, your camera should be pointed north. Polaris, the North Star, will be stationary in the center of circular moving stars. Between Earth and Sky illustrates this well.

In addition, the wider the angle of the lens you use the greater the curvature effect in the star trails. I exclusively use extreme wide angle lenses for these images, most of the time my 10.5mm digital fisheye lens.

The trick to exposing the multiple images is to expose for the starlight itself. This means at ISO 100 each individual exposure should be about four minutes at f/4 or f/5.6. (I’ll also be experimenting with using ISO 200 for the sensitivity setting.)

If you stack 12 four minute exposure times you get a total elapsed time of about 48 minutes. To achieve this, you need a sturdy tripod and a programmable timer. In this example, you put the camera on manual exposure and Bulb. Next, set the time for 12 exposures, each of a duration of four minutes, with a four minute and one second interval between the start of each exposure.

It’s important to turn in-camera long exposure noise reduction off. As I noted earlier, this gains you battery life (and noise reduction for the four minute exposures wouldn’t help you much with the star trail portions of the images). If you left in-camera noise reduction on (which I generally do for longer “straight” night time exposures like Stars Rush In or Tennessee Beach at Night), the elapsed duration following the start of the exposure would be far greater than four minutes, and the four minute and one second interval setting wouldn’t work. Even if you could figure out the right interval, the “missing” time would leave gaps in the trails.

I often like to also expose a longer exposure of the foreground, for example eight minutes at ISO 100 and f/2.8. I’ll use in-camera long exposure noise reduction on this one, so the actual time it takes is close to 16 minutes. If this foreground exposure turns out well, I’ll blend it into the composite using a layer mask and gradient. Here’s more about post-processing stacked star trails. Worth noting: I use the Unsharp Mask filter on the Luminance channel of the star trails, to bring out their detail, but I leave the foreground relatively soft.

Here are some of my recent stacked images in the order I made them (so you can witness my learning curve!), with links to the stories I wrote about creating the images.

Night Vortex Within the Photoshop Statistics script, the default setting, Mean, produced some kind of average sampling, not a very striking result. Standard deviation was interesting, but not ultimately satisfying. Range was good, but Maximum was best. My assumption is that this blended in the maximum value for every sampled point, so it makes sense that it produced the brightest star trails….Night Vortex
Between Earth and Sky First I tested the light with a one minute exposure at ISO 800 at f/3.5. Then I made an eight minute ISO 100 exposure (with in-camera long exposure noise reduction enabled) for the foreground. This image in its entirety is found below (I think it is interesting in its own right, with the still stars at the center and circular star trails around the edges)…..Between Earth and Sky
Yosemite by Moon and Star This one is a combination of sixteen exposures, taken early enough in the night that the moon was still lighting Tenaya Canyon and Half Dome….Yosemite by Moon and Star
Down in the Valley Taken from old Inspiration Point, this image uses a layer mask and gradient to combine a brighter foreground image with a stacked set of captures exposed for the sky and stars….Down in the Valley
Starry Night Many of my night photos are created in homage to Vincent van Gogh, who wrote in a letter to his brother Theo, “It often seems to me that the night is much more alive and richly colored than the day.” The star swirl in this image seems particularly van Gogh, so I thought I’d name this one Starry Night, after one of his most famous works….Starry Night
Starry Night 3 This fisheye starry night stacked photo from Glacier Point consists of 12 captures at four minutes and ISO 100 and f/3.2, and one high ISO capture at four minutes and ISO 800 and f/4. The bright purple comes from sensor flaring in the higher ISO capture in the stack. I intentionally left the foreground dark (the way it looks in the individual exposures) rather than trying to blend in a brighter foreground….Starry Night 3
Bridge and Stars Last night at Kirby Cove the weather was balmy. I ate a chicken sandwich from Bakesale Betty’s in the dark and called home to say goodnight to the kids while the timer took care of generating thirteen exposures, each at four minutes and f/5.6 (ISO 100). I had to throw away one of the exposures later because the airplane trails in it were just too distracting….Bridge and Stars
Edge of Night Against the backdrop of pounding surf and a light mist on the ocean, I photographed star trails behind Point Reyes Lighthouse in this portrait of the edge of night….Edge of Night
Night View of Bodega Bay This view is looking north out from the tip of Point Reyes across Bodega Bay. This is a storm-bound, windswept coast, often shrouded in fog, so I was lucky to get clear skies for the star trails….Night View of Bodega Bay

Starry Night 3

Starry Night 3, photo by Harold Davis. View this image larger.

We Are Not Alone

We Are Not Alone

We Are Not Alone, photo by Harold Davis. View this image larger.

Mark and I climbed to the top of a hill in Tiburon. There was a clear view north towards the Richmond Bridge. At this time of year, the sun sets early, and soon it was getting darker and colder. Fog was coming in through the Golden Gate and spreading across the Bay, but the northern vista was still clear.

This is a stacked composite consisting of 15 exposures made with my 10.5mm digital fisheye lens. Each exposure was shot at 4 minutes, ISO 100, and f/5.6. The total elapsed exposure time was thus about an hour.

Note that with all the ambient light in the city sky, the star trails are not as bright as they are in a darker environment. For example, the stars seem very bright indeed in this version of Starry Night, which shows the Yosemite sky.

The green line across the foreground is a ferry boat that made its way into Larkspur during a couple of the exposures.

Bridge from a Different Angle

Bridge from a Different Angle

Bridge from a Different Angle, photo by Harold Davis. View this image larger.

There’s always a new angle from which to photograph the Golden Gate Bridge. This image is from the trail on my way up from Kirby Cove on my way to Battery Spencer and the parking lot.

[Nikon D300, 18-200mm VR zoom lens at 18mm (27mm in 35mm terms), three exposures combined in Photoshop, each exposure at f/5.6 and ISO 100, tripod mounted: 240 seconds, 90 seconds, and 60 seconds.]

When Katie Rose Smiles

Katie Rose's Smile

Katie Rose’s Smile, photo by Harold Davis.

When Katie Rose smiles…

  • I see the promise of new beginnings
  • I sense her joy in discovery
  • I feel the melting of my heart
  • I know we are all connected
  • I believe the world will be okay

Katie Rose was two months old yesterday “gestationally corrected.” Meaning, if she had been born when she was supposed to be born instead of born early she would be two months old. She is acting for all the world like a normal, happy two-month-old baby.

Night View of Bodega Bay

Night View of Bodega Bay

Night View of Bodega Bay, photo by Harold Davis. View this image larger.

This view is looking north out from the tip of Point Reyes across Bodega Bay. This is a storm-bound, windswept coast, often shrouded in fog, so I was lucky to get clear skies for the star trails.

I exposed the photos used in this stack using my backup camera, a Nikon D200, while I photographed Point Reyes Lighthouse (Edge of Night) with my other camera (a D300). I had two tripods with me, but this one was kind of minature so I had to wedge it into the gap between a sign and the fence.

Compared to the D300, the D200 sensor seems to really heat up, which is where the purple flares come from. I kind of like them. Here’s another example showing the D200 sensor flaring, these star circles are from Yosemite at night.

[Nikon D300, 12-24mm zoom lans at 12mm (18mm in 35mm terms), 12 exposures each at 4 minutes, f/4, and ISO 100, total exposure time about 48 minutes, stacked in Photoshop using the Statistics action, tripod mounted using a minature tripod wedged between a National Park Service sign and a safety fence.]

Edge of Night

Edge of Night

Edge of Night, photo by Harold Davis. View this image larger.

Against the backdrop of pounding surf and a light mist on the ocean, I photographed star trails behind Point Reyes Lighthouse in this portrait of the edge of night.

Related image: Night at Point Reyes Lighthouse.

[Nikon D300, 10.5mm digital fisheye, foreground 10 minutes at f/2.8 and ISO 100, background 13 stacked exposures at 4 minutes and f/4 and ISO 100, total capture time about one hour, tripod mounted.]

Under the Bridge

Under the Bridge

Under the Bridge, photo by Harold Davis. View this image larger.

Briefly noted: Multitasking while shooting star trails for stacking at Kirby Cove, I captured this view of the North tower of the Golden Gate Bridge with the Bay Bridge underneath. A somewhat different take on the same composition as 2 Bridge Vu (third down on the linked page). The point of the photo for me is the reflection of the tower on the water, and how it visually behaves over the course of the two minute exposure. Here’s another bridge tower reflection in the surf.

[Nikon D300, 18-200VR zoom lens at 46mm (69mm in 35mm terms), 60 seconds at f/8 andf ISO 100, tripod mounted.]

Bridge and Stars

Bridge and Stars

Bridge and Stars, photo by Harold Davis. View this image larger.

Last night at Kirby Cove the weather was balmy. I ate a chicken sandwich from Bakesale Betty’s in the dark and called home to say goodnight to the kids while the timer took care of generating thirteen exposures, each at four minutes and f/5.6 (ISO 100). I had to throw away one of the exposures later because the airplane trails in it were just too distracting.

It’s surprisingly hard to eat a Bakesale Betty chicken sandwich in the dark.

The ambient light from San Francisco made the stars relatively less bright compared to the wilderness, and I wasn’t pointed north so my circles were smaller.

I combined in an eight minute exposure at f/4 to get the details of the beach, so my combined exposure time was about 54 minutes. It’s amazing what happens to lights and motion over this much time, witness the stars, reflections in the water, and if you look carefully the telltale lights of a huge container ship passing through the Golden Gate. (You can see this better in the larger size.)

[Nikon D300, 10.5mm digital fisheye, 12 captures at 4 minutes each and f/5.6, one capture at 8 minutes and f/4, all captures at ISO 100 and tripod mounted, combined in Photoshop using the Statistics script.]

Same Fuschia This Year

Fuschia Gradient

Fuschia Gradient, photo by Harold Davis. View this image larger.

Down the block, in front of Heidi’s house, there’s a great fuschia that grows buds like this one (Jet Engine and Doodling show buds from the same plant last year). Fortunately, Heidi has given me permission to snip buds whenever I like, so I can have an affair with the flowers every year.

This bud was photographed on a light box using a macro lens and extension tube. In Photoshop, I converted the image to LAB color. Next, I inverted the image (to get the black background) and combined the inversion with the original using a layer mask and a gradient blend.

[Nikon D300, 100mm f/2.8 Zeiss macro lens, 36mm Kenko extension tube, 3 combined exposures from 1/2 a second to 2 seconds, all exposures at f/22 and ISO 100, tripod mounted (using a Kirk Mighty Low Boy).]

Carrying Katie Rose

Carrying Katie Rose

Carrying Katie Rose, photo by Harold Davis.

Katie Rose is thriving. Tolstoy wrote that “happy families are all alike.” Indeed, there’s not much to tell. Carrying Katie Rose is like carrying a normal two-month-old, and it is easy to forget how small she once was, and what a miracle she is. I feel blessed every time I see the intelligence behind her gaze.

I’ve written a “report” about the day Katie Rose was born; you can read it here.

Merced Reflections

Merced Reflections

Merced Reflections, photo by Harold Davis. View this image larger.

Briefly noted: Along the Merced River the seasonally low water was totally still in the morning, leading to crystal clear reflections.

[Nikon D300, 18-200VR Zoom lens at 50mm (75mm in 35mm terms), circular polarizer, 3 exposures combined in Photoshop from one to six seconds, all exposures at f/32 and ISO 100, tripod mounted.]

Glory

Glory

Glory, photo by Harold Davis. View this image larger.

Crawling out of my sleeping bag to the sounds of a massive rock slide (here’s the story), I found the Yosemite Valley floor filled with dust. Whatever the cause, the crepuscular rays wrought by the rising sun struck me (and the other observer in this photo) as glorious and spectacular.

Essentially monochrome, I converted the image to black and white in Photoshop using multiple black & white adjustment layers (my process for b&w conversion is partly explained here).

[Nikon D300, 18-200 VR Zoom lens at 32mm (48mm in 35mm terms), 1/400 of a second at f/5 and ISO 100, handheld.]