The Terra Galleria Blog – QT Luong

What ISO should you use for lowest noise ? Everybody knows that low ISO will result in lower noise and high ISO will result in higher noise.

But is it a continuum, as one would intuitively think, or are some ISOs better than others ? In the past, I had seen advise to use only whole f-stop ISOs (100,200,400,800,1600,…) because intermediate ISOs were presumably “interpolated” and therefore worse.

I recently watched part of a DSLR Video online class given by Vincent Laforet for creativeLIVE. There was plenty to learn on the video side. As a still photographer what surprised me the most was his statement that with Canon cameras (his experience was with 1D4, 5Dmk2, and 7D), one should shoot at multiples of ISO 160 for lowest noise. For example he mentioned that there was less noise at ISO 1600 than at ISO 1250.

This piqued my interest enough that I decided to conduct a “scientific” test myself. Instead of just relying on visual estimation, I would make actual measurements using Imatest software. As readers of this blog know, in the past, I had extensively used Imatest to assess lens quality, but the software has many modules that can assess any aspect of image quality.

I photographed a Kodak Q13 greyscale with a Canon 5Dmk2, using ISO values from 50 to 6400. The images were shot in RAW, and then converted to JPG with all settings zeroed, and resized down to 2600 pixels wide. Since noise is problematic only in the shadow areas, I restricted the analysis to the 10 darkest patches of the chart, using the Imatest Stepchart module.

The following graph attempts to summarize the results with a single number, the luminance (Y) noise in pixels. For an explanation of this measurement and how it is computed, please refer to the Stepchart manual page.

Here are what we can read from the graph:

• Lowest noise is at ISO 50, then ISO 100
• ISO 160 is better than ISO 125, and the same (*) as ISO 100
• ISO 320 is better than ISO 250
• ISO 640 is the same (*) as ISO 500
• Above ISO 640, noise increases as ISO increases

(*) a difference of 0.01% is not significant.

Conclusion: While at high ISOs (above 640) noise behaves as expected, at lower ISOs 160 multiples do provide the best results. More precisely, compared with the 1/3 lower ISO value, 160 multiples provide less noise and 1/3 higher speed. 160 may even be a better choice than 100, since it provides 2/3 higher speed and essentially the same noise. The exception is the special ISO setting of 50, which provides the less noise of all, but at the expense of less dynamic range.

What do you think ? Consistent with your observations ? (Scroll down past graphs to see comments)

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For reference, I am providing below the numeral values, and then complete output of the calculations. Again please refer to the Stepchart manual page for explanations.

ISO  Noise
50   0.80
100  0.94
125  1.04
160  0.95
200  1.03
250  1.13
320  1.11
400  1.22
500  1.38
640  1.39
800  1.57
1000 1.78
1250 1.89
1600 2.14
2000 2.50
2500 2.91
3200 3.41
4000 4.02
5000 4.75
6400 5.65

I may be a bit partial because of my Vietnamese background, but after visiting all the countries of continental South East Asia, and many others, I’ve found Vietnam to be one of the most diverse, enriching, exotic, and visually interesting countries in the world. Vietnam has it all: extraordinary natural landscapes, captivating historic cities, an ethnic mosaic of friendly people, and a traditional rural life that has not changed in centuries.

The coastline is highlighted by mountains dropping into the sea in Central Vietnam, and thousands of limestone karsts in Halong Bay. Soaring peaks culminate near Sapa, where colorful minority tribes make a living on impossibly steep slopes. In the mysterious Mekong Delta, all life – even public markets – centers on the water. Besides its natural beauty, Vietnam is home to a civilization dating back 4,000 years, which have produced a performance art, water puppetry, and a religion, Caodaism, not found anywhere else. Imperial palaces, citadels, temples, ancient ruined Champa cities and old trading ports, all contrast with the energy of modern Vietnam.

My images of Vietnam have been published worldwide, including on the cover (and opening spread) of a Vietnam issue of GEO magazine, and then on the cover of a dozen other brochures, magazines, and books. The very first photo gallery on this site (see site timeline) portrayed Vietnam in 2001. That same year, in order to share with other photographers some of what I’ve learned, I posted the photo.net photographer’s guide to Vietnam. It had taken me 10 weeks of travel to find the visual highlights of the country described in the guide, but Vietnam is small enough that it is possible to experience the most quintessential sights, which include all of the above and more, in a fast-paced two-week tour.

I am pleased to announce that I will be leading such a tour, Classic Vietnam in Focus, in the Fall of 2012 (Oct 25 – Nov. 10). For those who have less than 2 weeks time, the itinerary is broken down in 2 sections. The main section takes place on the plains (12 days) with an extension in the mountains (5 days) which can be taken separately.

The tour is organized by Insiders Asia tour director, Phuoc Babcock. Although her company is new, she has extensive experience in the travel industry, having led more than 30 tours. We will be traveling in style, staying at five star hotels (except in Hanoi, four star).

Our journey will take us through the whole length of the country, from Mekong Delta in the South to the border with China in the North, visiting the three main cities of the country, Ho Chi Minh City, Hue, and Hanoi. We will ride boats large and small in the busy waterways of the Mekong Delta, the famed Perfume River on our way to imperial mausoleums, the fantastic Ha Long Bay, and the Chay River bordered by mountains. Our scenic drives will include the Hai Van Pass, one of the most beautiful coastal roads in the world, and the remote route from Sapa to Can Cau. We will stroll through the architectural museum that is Hoi An bathed in the warm glow of paper lanterns during a festival, and trek to remote minority hamlets in the mountains. Our sights will range from majestic palaces and temples to colorful rural markets.

Unlike in ordinary tours, the emphasis will be on sites with the greatest photographic potential, and we will make sure we are there at the best time of the day to capture great light. Other tours may visit the same locations, but look carefully at our timings. Just to take the example of Central Vietnam, besides planning our visit for the Lantern Festival, we will leave at 5am to be for the sunrise at My Son, and then visit its fish market at sunrise the next day. We will stop in Lang Co overnight, therefore enjoying great scenic opportunities both at sunset and sunrise in this fishing village where other tours only do a quick mid-day stop (if they don’t miss altogether the Danang-Hue drive).

In the evenings, a workshop session focused on tips to improve your photography will include a group slideshow that helps us remember the day, as well as individual sessions customized for each participant’s level, where I will answer any questions related to photography, post-processing, and the photography business.

When is the best time to travel to Vietnam? Now — for tomorrow things might not be the same in this rapidly evolving country. Come and join me on this incredible journey to Vietnam. With your camera, you can capture a part of your experience that may not be there tomorrow.

Update Aug 2002: sold out

Detailed information about Classic Vietnam in Focus photo tour.

Melaka being a popular tourist destination just two hours away from Kuala Lumpur, Malaysia’s capital, I expected it to be a breeze to book bus transportation, but it turned out not to be the case. First, you’d think that the area around the Jalan Petaling street would be full of travel agencies, but I managed to find only two of them, each located upstairs, away from the street. Both of them told me that I had to go to the bus station to make reservations. Given that it had taken us three hours to get here from the bus station, I had no intention to waste a great part of the day, despite the warnings in the guidebook that one should not just show up and hope to get seats. The easy option was to go on a tour, but after reviewing their schedules, I thought that they would be inadequate for photography.

We took a taxi to the bus station before the crack of dawn. As the city was still sleeping, It just took us twenty minutes to get to the bus station. As soon as the taxi arrived, a man asked us where were were heading, and directed us to a bus. I was a bit wary of bypassing the official ticket booth, but the price seemed in line with the guidebook, and when I asked the man at what time the bus would be leaving, he promised only a half-an hour wait. It turns out that there are a lot of competition from bus companies, with hourly departures, so it wasn’t a problem at all to get seats.

The bus arrived at a station a few miles out of town, and a short taxi ride took us to the Chong Hoe Hotel in Chinatown. It was facing a Hindu temple. Next was a mosque, not any mosque, the oldest functioning mosque in Malaysia (1728). Down the street, we could see a traditional Chinese temple.

Compared to Kuala Lumpur, even Penang, the historic center of Melaka city appeared much more compact and relaxed. There were many tourists in the town center, most of them from Malaysia, and having a good time.

Contributing to the vacation atmosphere, Melaka had the most kitsch collection of trishaws that I had seen anywhere. Trishaws are the local version of the fun three-wheeled, human propelled vehicle seen with regional variants in most of Asia. Modernization has caused trishaws to disappear in most places, but here, they have been revitalized by tourism. Decorated with plastic flowers, they are even equipped with a sound system blasting loud music during the rides, which often start on the historic town square.

See more images of Melaka City, Malaysia

I had initially planned to travel by sleeper train from Penang to Kuala Lumpur. Making arrangements proved surprisingly difficult. None of the travel agents in town would handle train reservations. When I called the official railway office, I was told that reservations could be made over the phone only if the planned journey was at least 72 hours away, and that economical class sleeper seats were sold out. At that time, I didn’t realize that there is a railway station on Penang Island – although no trains ever stop there as the station does not even have rail tracks – and I wasn’t eager to take the ferry to Butterworth just to make a booking, while there was so much to see in Penang. I made reservations for a bus trip instead, which was easy since a bus leaves hourly, and all the agents could make reservations for it.

A minibus picked us up at the guesthouse and dropped us at the main bus station. The trip took about 5 hours as planned, but when the bus arrived, I could not identify the surroundings. Instead of stopping in the centrally-situated Puduraya bus station, the bus dropped us far in the countryside ! As we took a taxi to central Kuala Lumpur, I realized that we were at least a dozen miles away from the city center. Later, I understood that the Puduraya bus station was closed for renovation. The highway traffic was total gridlock, one of the worse I’ve seen, making the San Francisco Bay look tame in comparison. It took us 3 hours to cover the relatively short distance. I wished I had persevered in making the train reservation. Even though we had hired a taxi, finding the Hotel China Town Inn wasn’t straightforward. It is situated on Jln Petaling street, which is taken over by the busiest street market in the city in the afternoons and evenings: no vehicle traffic, thick crowds, and a jumble of stands stood in the way as we looked for the hotel.

Past this longer than expected trip and chaotic arrival, Kuala Lumpur proved to be a vibrant city full of contrasts. We had just time to make it to Menara KL , one of the world’s tallest observation towers. We took a walk in a well-preserved tropical forest right below the futuristic tower. The observation platform at the top offered a great view of the city, revealing its surprising amount of greenery. I arrived just a bit in advance of dusk and claimed a spot facing the iconic Petronas Towers. I was able to use my tripod, but I had to shoot through glass windows. Thanks to the great Dryclime jacket from Marmot, that I was carrying in spite of the tropical heat because it has a velvet-like black liner, I was able to block reflections from the inside lights for daylight and dusk shots, however, by night, the reflections caused by the double glass could not be overcome.

The next day, below the skyscrapers, I explored the ethnic neighborhoods which offered a mix of temples, street markets and food stalls as bustling and multicultural as anywhere else in Asia. However, what struck me most in the city was the diversity of the buildings, brilliantly illuminated by night, which reflected the fascinating mix of Chinese, India, Malay and western influences making up the country.

View more images of Kuala Lumpur, Malaysia

Kobuk Valley National Park is located in Northwestern Arctic Alaska, entirely above the Arctic Circle. It has the distinction of being the least visited of the 58 US National Parks.

Following our summer 2001 trip to Lake Clark National Park, the expedition to Kobuk Valley National park in 2002 was the first wilderness trip that Lanchi and I undertook after our wedding. This started by driving to Healdsburg, a town near the Russian River which is one of the most popular river rafting runs in California. There, we rented an inflatable canoe from SOAR. Their boats have the reputation of being rugged – you don’t want to get a leak in the middle of the Alaska wilderness – yet, when deflated they collapse to a small size, making them transportable by plane.

Armed with the SOAR boat, we flew (using again Alaska Air miles) to Kotzebue, the largest Eskimo community in Alaska, situated just north of the Arctic circle, on the coast of the Bering sea. From there, we boarded the mail plane to the Eskimo village of Ambler, situated East of the park. A kind villager offered us a four-wheeler ride from the airstrip to his family’s stand of drying white fish (see here) next to the river. We inflated our boat, and soon we were off for a week-long, hundred miles river journey down the wide Kobuk River through Kobuk Valley National Park, to the Eskimo village of Kiana, West of the park.

Floating downstream, we were hoping for an easy and relaxing trip, but the river was so placid that we ended up having to paddle all the time a boat that wasn’t tracking particularly well, probably because it is rudderless. Mid-way through this journey, as the night was approaching, a torrential shower came out of nowhere. We debated pulling to shore to seek shelter, but instead opted to continue, since we thought we were close to our objective. As we were getting soaked to the bone, we felt relieved to reach a characteristic wide bend of the river. As the rain started to ease, we set up camp on a bluff, planning to hike the next day. The next morning started by building a fire. After a few hours, all of our clothes, that we held up to the fire, were dry.

We hiked for a couple of miles, and at last set foot on the Great Sand Dunes, the most distinctive feature of the park. The unexpected sight is the largest dune system in the Arctic, a relic of the last ice age, when glaciers deposited sand there. The huge dune field was reminiscent of the deserts, but many clues pointed to its Arctic location.

I set up the large format camera. I looked for an angle where the ripples of the dunes would have the most contrast, eventually settling for a composition with a diagonal ridge line pointing to a group of black spruce trees, balanced by a more distant group of spruce trees – one of the clues we were in the Arctic. Because of the cloudy skies, the light wasn’t the best. Nevertheless I clicked the shutter in a celebratory mood. This was the moment I had been waiting for.

Next, I focused on the caribou tracks – another of the Arctic clues – that were crossing the dunes. There was still one element of the Arctic dune environment that I almost missed, the curious “reverse oasis” experience, where I was standing on a huge island of sand surrounded by lush vegetation in fall color as far as I could see – we had timed our trip on the last week of August for the foliage, as well as for the beginning of the caribou migration. Wandering near the edge, I found a spot where the two elements merged gracefully. At this point I had only one unexposed sheet of film left with me, so despite of all these years of experience, I proceeded even more slowly than usual, taking extra precautions not to make a technical mistake that would ruin the film.

Once I exposed it, and although the trip was far from being over, I felt that the last item on a decade-long to-do list could finally be checked off. Kobuk Valley National Park was the last of the 58 National Parks that I needed to visit in order to complete my project to photograph all of them in large format. The goal had been attained, but what I cherished the most was the journey. It continues to this day.

View more images of Kobuk Valley National Park
View more images of Great Kobuk Sand Dunes

Because of the weather in Ko Phi-Phi, I decided to shorten the stay in Thailand and spend more time in the cities of Malaysia. Rainy weather isn’t great for photographing (or even enjoying) tropical islands, but it doesn’t matter that much in a city, if you are concentrating on architecture and people.

The next stop would be Penang. I had initially planned to travel by train down the Malay Peninsula, but after a bit of research, I concluded that for this leg of the journey, taking a mini-bus would be much simpler. To journey by train, you’d have to find transportation from the Krabi passenger boat terminal to Krabi town, then catch a bus to Hat Yai. From there, get on the train to Butterworth and then take a bus or ferry to Penang. Instead for about 800 Baht ($26), a mini-bus would pick up us at the pier, and then drop off us right at the Love Lane backpacking district in Penang. By now, I wasn’t surprised anymore when the mini-bus went around town to pick up additional passengers, even when it appeared to be full. I was just a bit concerned for the passenger who was sitting on the floor for such a long journey, but he actually hitched only a short ride to a bus station. The 11 hours trip was broken up by a lunch stop, a change of bus in Hat Yai (during which we were provided immigration forms for Malaysia), and the actual crossing of the border, where we had to disembark and carry our luggage for inspection. No advance visa is required of US and ASEAN citizens for a short stay in Malaysia.

By the time we arrived in Penang, it was quite late. The “SD Guesthouse” listed on the Lonely Planet had gone out of business, and most of the Love Lane hotels had filled up. After settling for a cheap Chinese hotel (that I’d call a dive, although the owner was friendly) for the night, we moved the next day to the Banana Guest House since my cousin didn’t like having to go in the courtyard downstairs for the bathroom, and I wanted a wireless internet connection to stay in touch with family through Facetime.

Even though it rained a lot, I found the historic district of Georgetown (the main city on the island, which for most visitors is Penang) wonderful to explore on foot, as it was compact and full of historical buildings, ranging from mansions, to assembly houses and temples. I noticed more diversity than in any other place I’ve visited in Asia, with British Colonial, Indian, and Chinese influences. Buddhist, Muslim, and Hindu religions appeared to co-exist peacefully. Highly recommended !

View more images of Georgetown, Penang

The National Park of American Samoa is located in the South Pacific, in the Southern Hemisphere, right in the center of Polynesia, making it the most remote of the 58 National Parks. Its slightly different name (not “American Samoa National Park”) reflects on its status: The National Park of American Samoa is situated on a US Territory, its lands are all leased from Samoan villages which are the true landowners.

The distance to the continental US is certainly the reason the National Park of American Samoa is the second least visited of the 58 US National Parks. To get there took me ten hours of flight from California, plus a stop over mid-way in Hawaii. If it was closer, I’d expect that park to be a popular unit. It is one of the most beautiful parks, graced with magnificent sand beaches and pristine coral reefs, bordered by tropical rain forest islands ringed with impressive cliffs.

The park comprises sections of three islands, Tutuila, Ta’u, and Ofu. The later two are part of the group of Manu’a islands, a half-hour flight from Tuituila, the main island. Since it was such a long trip to get there, I made sure to visit all three of them. The least visited island on that most remote park is Ta’u Island, where the Park doesn’t have any facility. As camping is not allowed and no commercial lodgings were available, I made arrangements for a home stay with a Samoan family with some help from the NPS office in Tuituila.

As I disembarked from the small prop plane and walked to the tiny office, my host had no problem finding me: I was the only visitor. I loaded my gear on the back of his pick-up truck amongst a jumble of pandanus leaves and coconut hulls. We drove on through a beautiful coastal road which was totally empty, and arrived at Fiti’uta, a village consisting of maybe a dozen houses and the traditional communal Fale.

The Samoan culture is Polynesia’s oldest. The first people on the Samoan islands came by sea from southeast Asia some 3,000 years ago. However, Samoans believe their God Tagaloa created the first man and woman on Ta’u and that all people descended from them. Ta’u is also the site of Margaret Mead’s landmark study for Coming of Age in Samoa (1928) which was for forty years the most widely read book in the field of anthropology. My host’s wife had prepared a great looking dinner, but since I am a vegetarian, I had to content myself with taro roots. The next morning, my host drove me past Sau’a, that mythical site of the creation of humanity according to Samoan beliefs. He dropped me at the end of the dirt road, named Siu Point. I would not see another person there.

The coast was the wildest I had ever seen. After my first glimpse of it, I tried to hike along the shore in order to get closer to the sea cliffs that I saw in the distance, which I read were the tallest in the world. However, I was making slow progress, as I had to hop from boulder to boulder with my heavy backpack. The black, volcanic boulders were quite sharp. Seeing that the perspective did not change significantly, I turned back in order not to be late for the evening pick-up.

I had initially planned to stay only two days on Ta’u before flying to Ofu, but my host told me that the flight for the next day had been canceled due to an incoming storm. Since there was only a flight every two days, this meant two more days on the island. At the time of my visit, information about Ta’u was scarce, and I was aware of the trails to Laufuti Falls or Lata Mountain. My understanding was that the other parts of the National Park on Ta’u consisted of a roadless jungle inaccessible without a guide with whom I would have needed to make arrangements with in advance. Therefore, all my host could do for me was to drop me off again at Siu Point. Past the disappointment of having to shorten my stay on Ofu, and revisiting the same spot, the prospect of a tropical storm was actually quite exciting, so I prepared myself for a wet day, since there is no shelter there, and I would be on my own for the day.

Fortunately, it poured only for brief moments, that I waited by sitting under my umbrella. The rain actually proved a welcome respite from the tropical heat. In the end, it is as if the Polynesian gods chose to reward my perseverance by rainbows, a show of big crashing waves under a dark sky, and then dramatic light at sunset. Just as the dark clouds were starting to yield an intense shower, I saw the headlights of my host’s truck. On the way back, as it rained so hard that it was difficult to see the road through the glare of the lights, I could see his surprise when I told him that I had a great day.

See more images of American Samoa
See more images of Siu Point

Cuyahoga National Park preserves a small section of rural landscape along the Cuyahoga River between the two large cities of Akron and Cleveland in Ohio. Like for Black Canyon of the Gunnison, I visited Cuyahoga late because it had just been designated a National Park the year before.

At first, expecting the traditional terrain of a National Park, as I drove the length of the park, I was left wondering where the National Park actually was ! In many other National Parks, the hand of man is present in a subtle way, even if the landscape looks pristine at a first glance. In Cuyahoga Valley, the impact of man was anything but subtle. The area that I crossed had many roads, agricultural lands, recreational parks with lots of facilities, a golf course. Private homes were even all over the place. Many portions of my adopted city, San Jose CA, are more wild. I eventually drove past a “Cuyahoga National Park” entrance sign, so I had to tell myself “that’s it”.

After I got past my expectation, I began to understand the significance of the place. By the middle of the 20th century, it was a dump. Once I realized that this once heavily polluted valley could have been restored so that there were now plenty of pockets of natural beauty, I began to appreciate them more.

One of the largest lakes in the area is situated within Virginia Kendall Park, in the eastern section of the park, southeast of the small town of Peninsula. The 13 acre Kendall Lake was created by damming the Salt Run creek (a tributary of the Cuyahoga River) by the Civilian Conservation Corps in 1935, part of FDR’s New Deal extensive program of public works. Rehabilitated in the early 2000s, the dam keeps Kendall Lake filled with water and controls the outflow to Salt Run.

Following a mile-long loop trail, I walked several times around the shore of Kendall Lake, at different times of the day, on different days, experiencing different weather. Surrounded by a varied mixed woodland, and cattails, home to beavers and Canada Geese, the modest body of water offered much more than I thought it would. I reflected on the fact that I had to travel across the country to do such work, when I could have found many places similar to this close to the city where I live, and investigate them in even more depth. It might be all inside your mind, but it’s still necessary to take the journey to unlock it.

See more images of Cuyahoga Valley
See more images of Kendall Lake

As a multicultural family, we get to celebrate twice as many occasions ! Today is the lunar new year. We wish you and all your loved ones a year of the rabbit (cat for the Vietnamese !) full of happiness, health, prosperity, and success.

After Railey, my next stop in southern Thailand was Ko (island) Phi-Phi. I catched a long-tail boat ride at Railey East to the small pier of Ao Nammao. The tour operator with whom I had booked the trip sent a mini-bus – late by almost an hour and again packed to the gills – to shuttle us from there to the shiny Krabi passenger terminal, where we boarded a larger vessel for the hour and half crossing.

From the boat, we saw plenty of barely developed beaches, with just a few bungalows nearby, but by contrast Tonsai Village surprised me by being a wall-to-wall patchwork of tourist-oriented businesses. In particular, i had never seen as many dive shops before, offering instruction in any possible language. Yet the atmosphere was relaxed, with not a single motorized vehicle in sight.

The waters, crystal clear, must have been a stunning sight in good weather, when the sun could penetrate them to reveal their turquoise hues, but unfortunately the rainy weather continued. In those conditions, I thought it wouldn’t be worth it to take a boat tour, and instead wandered around with an umbrella. My most interesting discovery was a small muslim cemetery (at the bottom of this page), which, with its low profile graves, was unlike any of the cemeteries that I have seen before.

However, since staying for hours in a cemetery is no way to spend a tropical island vacation, despite the cloudy weather, I headed to the beach, which was lined up with long-tail boats.

The long-tail boats are an iconic watercraft in this part of the world. These ingenious boats use a common automotive engine, mounted on a turret which can rotate through 180 degrees, allowing steering, and also swivels up and down to provide a “neutral gear” where the propeller is outside of the water. The propeller is mounted directly on the driveshaft (with no additional gearing) through a long metal rod of several meters (see here) giving the boat its name. Since there are no roads on Phi-Phi Island, long-tail boats are the means of transportation for locals and tourists to destinations outside Tonsai Village.

Although the scene lacked brilliant colors, there was a sense of tranquility that I tried to capture. As I lingered for a long time there, I noticed that despite the overcast conditions, the light and pastel colors changed in a subtle way as the hours passed. The difference was enough to yield different images that feel different to me, even with a similar composition. Which one do you prefer, and why ?

View more images of Ko Phi-Phi.