Dennis Goulet — Page 3

Dennis December 23, 2011 3 Comments

Focus Stacking

A Technique to Increase Depth of Field of an Image

Ever notice how little is in focus when taking close-up images, even with the lens set at f/22? At the closest focus distance of a 100mm macro lens of 12 inches, the depth of field is only .33 inches at f/22 with a full-frame sensor, and only .21 inches with a cropped sensor body. Well, there’s nothing to be done about the laws of physics, but there is a technique that can be used to increase the range of focus in digital images. Focus stacking is the merging of the sharp sections of multiple image captures of the same scene. I became interested in this technique as an avenue to increase the depth of sharpness in my macro images, but it can also be useful in landscape images when circumstances require. What I most desire from this technique is the ability to have a subject sharp from front to back while maintaining a pleasing out-of-focus background.

I started my experimentation by capturing a series of images of an orchid on a recent trip to Costa Rica. At f/22, the range of focus did not capture the right and left orchid sepals in focus, and even if it did, such a small aperture resulted in more detail in the background than I wanted as seen in the first image below. I captured six images at f/13 with the intent of getting all parts of the orchid in focus, while rendering the background as softly out of focus as possible. I used a stacking technique in Photoshop CS5 to align and merge the images together. The second mage below is the composite image and even in this small sized image the complete focus of the flower and the more pleasing background blur are obvious.

This process is not a magic panacea for increasing depth of field. As this was my first time using this technique, I had several surprises; the composite orchid image was surprisingly well assembled, pulling together all the sharp elements of the image. However, there were some anomalies that required further editing to clean up the image, more about that later. Overall I was pleased with the result and throughout the summer I used the technique when the opportunity presented itself. My goal was to photograph a Rattlesnake Orchid that has been growing along the edge of the wooded section of my yard since 2005, and it has blossomed only twice; in 2008 and again this year. The blossom is a stem of many tiny orchids that grow in a spiral around the stem. I wanted to document this beautiful flower as well as the stages of growth, if I could.

One situation that focus staking serves as a useful tool it photographing a cluster or group of small subjects such as a cluster of mushrooms growing on the side of an old moss covered wood pile. The mushrooms I found have a deep ridged structure to the underside of the cap, and I wanted to capture this detail in a cluster of mushrooms. The span from the front edge of the mushrooms to the back edge of the most distant mushroom were about one inch. The first image is a single capture taken at f/22 and the second image is the composite image using 12 captures each at f/14 at 1/20 second and were aligned and merged using the Photoshop technique. The images were captured with a Canon 7D and Sigma 150mm f/2.8 macro lens mounted to a sturdy tripod. The starting point for capturing was determined by observation; I looked at the cluster of mushrooms from an angle that I could determine the edge closest to the camera, as well as the edge farthest from the camera.

To ensure accurate focus, and to accurately judge that the next section of the flower to be in focus overlapped the previous section, I used the Live View feature of the camera. Instead of viewing the image through the viewfinder to compose and focus, live view lifts the mirror in the camera and displays what the sensor will capture in the display on the back of the camera. It also has a feature to enlarge a small portion of the image, allowing critical focus.

When using a small aperture such as f/22, even a distant background shows some definition. In this example, while f22 captures the spider with adequate depth of field (DOF = .43 inch in this case), it results in too much detail in the background. As can be seen in this side view of an arrowhead micrathena, the distance from the top of the spinerets to the “arrow tips” of the abdomen is about 3/16 inch. To complicate matters, the spider was hanging from the center of the web. To isolate the spider and web from the background, focus stacking provides enough depth of field by blending several layers captured of the subject without extending significant depth of field to the background. The first image below is a single capture of f/22 and the second image is a composite of four captures at f8.

For the spider image, the web was also moving slightly in the breeze. Photoshop’s auto-align handled the slight offsets in position for each capture very well, and no artifacts from the process were evident.

Another good use of the focus stacking technique is the case where the subject is essentially flat, but the camera cannot be positioned so that the sensor plane is parallel to the subject. For this example I photographed water droplets on a window pane that formed due to condensation. A similar situation would be frost on the window in winter. I set the camera at an angle of about 15º in order to create the misalignment. The first image is a single capture at f/22. There is evident lack of sharpness on both sides. The second image is the last slice of 8 captures at f/8 with the right edge of the image in focus and the left side significantly out-of-focus. The thrid image is the 8 slice composite image and is sharp from edge to edge.

Focus staking has been demonstrated to be a useful tool to increase depth of field in these situations. There are anomalies that sometimes arise; some of which are easily fixed and others that are impossible to fix. In Part 2, I’ll present some of the image processing errors I discovered, and describe some methods to edit the final images. I’ll also describe my tests of the Helicon Focus software, a product specifically designed for focus stacking.

Focus Stacking – Part 2

Dennis November 27, 2011 Leave a Comment

Galapagos Islands 2011

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This was my second visit to the Galapagos Islands. My wife and I visited in April of 2005, and I never figured I’d return since I have a lot of other locations on my list of places to visit and photograph. This trip was one of the prizes awarded to me as grand prize winner in the 2010 Audubon Magazine photography contest. The cruise was provided by Lindblad Expeditions aboard the National Geographic Endeavor. Lindblad and Nat Geo do organize a great trip, with top notch naturalists, including a few trained by National Geographic photographers to provide advice and guidance to the less experienced photographers among the passengers.

text-untitled-0365 — Beach at Punta Pitt

Each day was similar in schedule, but widely different in experience. We’d awake anchored in the location for the morning excursion. Occasionally a choice of activities was offered which might include a long walk, a short walk, or just a stay on the beach but mostly one walk was offered. There was always an alternative activity, usually a zodiac ride along the coast, for those not wishing to take the offered hike. Most landings (all but two) were wet landings; the zodiac would get close to the beach, and the passengers in turn would get off into the water and wade to the beach. The water was never more than knee deep, and towels were provided on the beach to dry off feet and put on shoes for the walk. Upon embarking the ship from the morning excursion, we’d sail during lunch to a second location for the afternoon activity. Between shore excursions were afternoon lectures, occasional deep water snorkeling or kayaking opportunities.

The weather was mild and cloud covered for sunrise, with the clouds burning off as the day went on, with the afternoons mostly sunny. Seas were mostly calm even when on the edge of the archipelago north of Isabella Island. Sunrise photography was not great, and only one evening was good for sunset, with the exception of the last evening at sea, when we were circumnavigating Kicker Rock, unique rock formations which are the remnants of a volcanic cone. Just before we sailed away from this rock, the light turned golden and the rock appeared on fire. Based on the week of dull evening light, this last evening was spectacular. The ship was sailing into the sunset, I hurried to the bow of the ship, where both feet slipped out from under me, I landed flat on my face spread out on the deck, my camera skidded across the deck . . . and no one noticed. I dragged myself up and looked around; everyone was intently watching the sunset and hadn’t noticed my acrobatics at all.

Dennis October 30, 2011 Leave a Comment

Yellowstone National Park — Grand Teton National Park

23 September — 6 October, 2011

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At the end of September, my wife, Chris, and I visited Yellowstone National Park and Grand Teton National Park hoping to see and photograph the yellow and orange fall foliage, abundant wildlife preparing for winter, and perhaps a touch of winter itself. We arrived with the leaves just starting to turn, scant wildlife, and temperatures in the 80’s for the first few days. We did find a herd of 200 or so bison spread out in the Lamar Valley and on the return to Mammoth Hot Springs we found a herd of ten pronghorn does with a buck keeping order. One evening we also had a few bighorn sheep come down the cliffs to the Gardiner River. The first evening we planned on eating at the park dining room anticipating the evening show; 30-40 elk cows with two or three bulls vying to keep track of their respective harems, and try to coax a few more cows from another harem. We saw one nice bull, and four cows. Where did they all go? The introduction of wolves to the park did reduce the elk herds, but to a greater degree than initially expected. This was a result of the overwhelming success of the wolf packs, which have done better than predicted. The wolf/elk ratio has probably hit an equilibrium; if there are not enough elk for one reason, let’s say a bad winter, there will be fewer surviving wolf pups due to less food available, then the elk with have greater success, and then the wolf numbers will increase.

: Mammoth Hot Springs

We spent the first three nights based in Gardiner, MT, at the north entrance to Yellowstone NP. From there it is convenient to travel to the Lamar Valley, Tower Junction and the Canyon Village section beyond, and to Norris Geyser basin. Basically, the northern half of the park. Mammoth Hot Springs is the northern headquarters of the park services with lodging, dining, and conveniences (general store, fuel, post office, etc.). The springs for which the area is named, and the travertine cliffs here have changed over the years as geologic activity redirects the hot spring water below ground though subterranean limestone, dissolving calcium carbonate and depositing it as travertine (a bone white mineral) as the water cools on the surface. But that is not what creates the rainbow of colors at this, and all other, thermal features: it’s the thermopiles (heat-loving microorganisms). The color of the thermopiles is due to the temperature of the water. Cooler waters support the growth of orange, brown and green thermopiles while clear and yellow thermopiles thrive in the hottest water.

The Grand Canyon of the Yellowstone has several viewpoints to easily view and photograph both the upper and lower falls and the Yellowstone River. There are also a number of trails that lead down into the canyon for a more intimate view of the falls. We visited the canyon on different days and at different times of day to get a variety of light into the canyon. While overcast conditions greatly reduce shadows in the canyon, the light is not dramatic nor does it bring out the intense colors of the rock. The sun cast heavy shadow on half the canyon for our visit to the canyon at midday, and a return visit a few days later at 3pm with cumulous clouds in the sky provided a brightly lit inner canyon.

: Mount Mornt Reflection at Oxbow Bend

Our next stop was in Jackson, WY, near Jackson Hole and the Grand Tetons National Park. Since we were so late in planning this trip,we opted to stay in Jackson, even though we would have an additional 20 minute drive into the park for sunrise. Sunrise opportunities are numerous in Grand Teton; Schwabacher Landing, Oxbow Bend, Molton Barn and Mormon Row. In our exploration we found a beaver pond near the road (about a foot away from the road) where one evening we watched two adult and two young beavers feeding on the bark and leaves of small branches within fifteen feet of us. We visited the location several times during our four days in Jackson and did repeat the experience.

Again, wildlife was somewhat scarce, with the exception of the beaver. We saw several elk cows and a couple of bulls in the early evening hours, but did not see a single moose. We did see osprey on a nest but the position made photography impossible, and saw a red tail hawk flying. In any case, the landscape photography opportunities were reasonably decent, even though proscribe forest fires at the south end of the park resulted in ground smoke at the base of the mountains. This is evident in the images that show a grey pallor on the lower half of the mountains.

: Grand Prismatic Spring

We then moved on to Old Faithful Snow Lodge for the last five nights of our stay. This location gave us good access to the southern half of the park, and even drives to the Canyon Village area were not that far away. A large number of visitor accessible thermal features is in this area, including Old Faithful geyser. Photographing hot pools and geysers can be challenging as they produce large amounts of steam. Your luck will depend largely on the direction and speed of the wind, and the air temperature. On my winter visit here, there were times when you could hear a hot pool bubbling, but couldn’t see it for all the steam surrounding it. The higher daytime temperatures (low 70’s) while we were there offered up some interesting views of the thermal features. I concentrated on areas of the thermal features that had striking color or interesting compositions.

The wildlife activity did eventually perk up as the nights became cooler and the daytime heat finally abated. We saw several herds of elk along the Madison River, and bison herds could be seen at many locations with about 50 animals each, except for the big herd in the Lamar Valley. By far the best experience was viewing a pack of wolves in the Lamar Valley returning to an elk they had killed the day earlier. At one of the pull-outs overlooking Hayden Valley we overheard this tidbit of information from a couple that was deciding where to go next. One at a time the wolves would come to the carcass, chase off the ravens and magpies and try to pry meat from the bone. Since the carcass was in the river, one wolf tried to pull it up onto the bank to get at the meat that was previously submerged. Another big spectacle was the number of photographers who had lined up shoulder to shoulder in two locations.

Dennis August 3, 2011 1 Comment

Costa Rica 2011 The Art of Biodiversity – Part 4

Bosque de Paz Ecolodge

This small lodge, located in a valley between the Poas Volcano and Juan Castro Blanco National Parks offers a diversity of subjects to photograph. The owners, Federico and Vanessa González-Pinto are working hard, and succeeding in, developing an ecological corridor linking the two nationally protected areas. They are amiable hosts and are truly concerned for the nature of Costa Rica. In addition to the variety of landscape opportunities of the cloud forest moss-covered trees and rushing streams, the place is teeming with hummingbirds. There is also an extensive collection of orchids located near the main building that hosts hundreds of orchids, and the owners sponsor orchid research supporting preservation efforts. On the afternoon of our arrival, I spent some time photographing in the forest, and captured a few images of hummingbirds hovering near the feeders. The first orchid in the series is a stacked focus images, made from six images that have different zones in focus. I’ll be writing a blog post on the technique soon.

In addition to the local photographic opportunities, two setups for high speed flash photography were made available on the second day of our stay here and a schedule for use by the participants was established. Initially we set up hummingbird feeders to attract the hummers to the sets, but switched to flowers after the first round. While high speed flash set ups make photographing crisp images of hummingbirds possible, it’s difficult to predict exactly what the image will look like until you view the image. It’s a simple matter to take a photo of the hummingbird with its beak in the flower since it stays there for a few seconds, although you never know what the position of the wings will be. It’s much more challenging to catch the hummingbird approaching or departing from the flower, or if there is an altercation with another hummingbird. On several occassions the birds were landing on flower pants and breaking them off, making for a not-so-attractive flower. I walked over to coax a Green-crowned Brilliant off a flower and it stepped onto my finger where it stayed for a full minute. Luckily, I still held on to the wireless remote control and was able to capture some images.

On the third day of our stay at Bosque de Paz, we made a day trip to a nearby restaurant that has access to the 110 meter Bajos de Toros waterfall. There are trails through the forest and a set of stairs that descend to the base of the falls. Two hummingbird high speed flash setups were placed in the open air restaurant to take advantage of some species which were not found at Bosque to Paz. This was the first time I had seen a black-bellied hummingbird, a very small bird that fluffs the feathers on its head in a curious way when it is perched. When it is flying, the feathers are flattened aerodynamically.

After dinner at Bosque de Paz, a few of us ventured out around the lodge and down a path to find insects and frogs for some nighttime macro photography. We did find a small tree frog which was about ¾ of an inch in length, and we had great opportunities with a cicada which had just climbed out of its shell and was still damp and unable to fly. We all had our turn photographing this amazing insect by flashlight.

Dennis July 21, 2011 1 Comment

Costa Rica 2011 The Art of Biodiversity – Part 3

Arenal Observatory Lodge

Arenal is the country’s most active volcano, with continuous emissions of lava and incandescent pyroclastic flows since the beginning of the present active cycle in 1968. In 2010 when I visited this location, the eruptions could be heard day and night roaring, coughing and spitting, but due to the low cloud cover, not seen. I did get a view of the pyroclastic flows through a break in the clouds for about 30 seconds one evening. The weather did cooperate this year with clear skies one evening and clear skies one morning during sunrise. Unfortunately, the volcano stopped erupting to a great extent three months prior to our visit. It was quiet. You could still see steam coming from several vents in two locations near the summit, but no fireworks. The lodge grounds offer many gardens, and there was an extensive garden right outside our room where we could observe hummingbirds feeding at the flowers.

We spent one day at a nearby facility that houses a wonderful collection of frogs, toads, snakes, and lizards. The staff set up several stages with natural vegetation, moss covered rocks and stumps; the vegetation on the nearby hills provided out of focus backgrounds, and we could photograph with natural light or with fill flash as we chose. It was a great opportunity to photograph species which would be difficult, if not dangerous, to photograph in the wild. The facility also had a butterfly enclosure which I visited while waiting for the set ups to be ready. Once the stages were completed, several species were brought out and placed in the setup. An experienced caretaker stayed with the animal at each set up, repositioning the subject when it moved into a position that was not photographic. The caretaker would replace the animal when it appeared to be too active, or when photographic interest in that subject diminished. At the end of the day, one caretaker asked my wife Chris if she wanted to hold the Rainbow Python, which she did. She was surprised that it was very soft to the touch.

We also spent a morning at the Danaus Ecocenter. There was a limited number of birds in the area due to the time of year, but quality is often better than quantity. We had quite a long time with several Collared Aracaris feeding on fruit very close to the path. And one of the guides showed us the location of a baby three-toed sloth since it was not on one of the main paths, but on a service road.

All in all, Arenal Observatory Lodge is one of those locations in Costa Rica which could easily support a week’s worth of photographic subjects, if you know where to look. There are trails up through the forest to the lava fields and a large lake that we didn’t explore on this trip. However, unless you were on a Foto Verde guided trip, you wouldn’t have the opportunity to photograph the variety of reptiles that I did on this trip.

Costa Rica 2011 The Art of Biodiversity – Part 4

Dennis July 11, 2011 2 Comments

Costa Rica 2011 The Art of Biodiversity – Part 2

Selva Verde Lodge

We spent three days at this tropical rainforest lodge located on the banks of the Sarapiqui River. The attraction here is the abundance of green and black poison dart frogs and red poison dart frogs as well as masked and red-eyed tree frogs. One back lit basilisk lizard was a challenge to photograph as we tried to move through the undergrowth off the path and not chase the lizard off. There were also lizards climbing a tree next to the dining room, and we even saw a baby fer-de-lance on the side of the path. It couldn’t have been more than three inches in diameter coiled less than a foot from the path. The lodge naturalist moved the snake into the forest for everyone’s (and the snake’s) safety. When Greg was selecting some vegetation for nighttime photography of a red-eyed tree frog, he explained that we had to carefully look under the low vegetation to make certain no fer-de-lance were there. We could hear numerous birds throughout the forest, but they were elusive with the exception of a mot-mot, a chestnut billed toucan, and an ochre bellied flycatcher on the nest. We also had some time with howler monkeys which were very close and almost eye-level from the balcony of the lodge’s classroom. The naturalist believes they come to see their reflection in the floor to ceiling windows.

One morning we traveled to a nearby farm owned by a local family that has preserved some of its property as forest. Great Green Macaws and Scarlet Macaws live in the forest and stay close to the farm to roost and feed. He also had a large enclosure that injured birds, which locals had found were rehabilitated and allowed to go free. There is an opening in the cage where birds can come and go as they please. The owner also rescued two jaguars from being hunted and killed by local villagers for killing cattle. The farmer got the villagers to agree to let him capture the animals rather than just kill them. He built an enclosure to house the jaguars and takes good care of them; they look healthier than some zoo animals I’ve seen.

Costa Rica 2011 The Art of Biodiversity -Part 3

Dennis July 8, 2011 1 Comment

Costa Rica 2011 The Art of Biodiversity Part I

Chris and I traveled recently to Costa Rica with my friend and tour leader, Greg Basco, cofounder of Foto Verde Tours, a provider of tours designed for photographers. Last year I traveled to Costa Rica with Joe and Maryann McDonald primarily to photograph hummingbirds, and met Greg who organized and co-led the trip. This year I signed up early for the Art of Biodiversity tour which offered a wider variety of photographic subjects at the start of the rainy season. Chris decided to join me at a later date, which worked out well as there were only two other participants for a total of four plus Greg and Jose Lopez, our driver and also a very good photographer.

My blog entries for this trip will be divided by location, starting with the Bougainvillea Hotel in Heredia, near San Jose, the capital of Costa Rica. We also traveled to Selve Verde Lodge, the Arenal Observatory Lodge, and the Bosque de Paz Ecolodge as well as side trips from those locations.

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The Bougainvillea Hotel This was my third trip to Costa Rica and each time I stayed at the Bougainvillea to start and end each trip. Tour providers choose this hotel in a residential area for its 10+ acres of gardens that include over 50 species of bromeliads, native trees, orchids and frog ponds. Each visit offered different plants in blossom. And while my two visits in March had quite a few birds in the garden, in June the migratory birds were gone, and the local birds were raising chicks and mostly staying hidden. There were more plants in blossom, but fewer orchids. In any case, I wasn’t disappointed with the opportunities to use my macro lens.

Costa Rica 2011 The Art of Biodiversity – Part 2

Dennis April 21, 2011 2 Comments

Yellowstone National Park in Winter
Part 2

After attending the Natural Exposures Yellowstone in Winter Photo Tour described in Part 1, I picked up a rental car in Bozeman and continued my winter adventure based in Gardiner, MT. Gardiner is only a few miles from the north entrance to the park and Mammoth Hot Springs. Highway 212 passes through the northern section of the park to Cooke City just outside the northeast park boundary. This road is maintained year round and is the only means to reach Cooke City during the winter.

[Read more…]

Dennis March 3, 2011 6 Comments

Yellowstone National Park in Winter — Part 1

Yellowstone National Park in Winter — Part 1

I’ve always wanted to visit Yellowstone in winter to photograph the scenery and wildlife. After considerable internet searching, this year I signed on for a February trip with National Geographic contributing photographer Daniel J. Cox (Natural Exposures). The trip schedule included four day-long excursions by snow coach into the park from West Yellowstone and a day on either end to travel from/to Bozeman. Since I was going to travel to Montana, I added on three days of photographing the park from north entrance at Mammoth Hot Springs, the only area of the park that clears the roads for automobile travel during the winter. More about my independent travels in Part 2.

Part 1 is long and includes both my trip report and a review of the Natural Exposures Yellowstone in Winter Photo Tour for those considering this trip or this tour company. [Read more…]

Dennis December 26, 2010 7 Comments

Audubon Magazine Birds In Focus Winner

Web Dennis_Goulet_GreenbreastedMango — Green-breasted Mango

GRAND PRIZE WINNER

My image of a Green-breasted Mango was selected as Grand Prize Winner of the Audubon Magazine Birds In Focus photography contest. It was selected from the 8,000 entries in this year’s competition. The image is one of the thousands of images I captured during my trip to Costa Rica in March 2010. You can find the announcement of the winners at Audubon Magazine.

Another of my entries was selected as one of the Top 100 images of the contest and can be seen here. Rather than tell you which one is mine, I’ll leave it to you to explore all of these wonderful images. After you see these images, you’ll understand how honored I am that my image was selected from among those images.

Click on the thumbnail to view a larger image.