The Terra Galleria Blog – QT Luong

Canon makes two wide-angle zooms for full-frame cameras. Both are L-lenses, reasonably well-built, with fast USM autofocusing, a non-rotating front element, and an environmental rubber seal. The 17-40/f4L was introduced in 2003. The 16-35/f2.8 L II, released in 2007, replaced the 16-35/f2.8L of 2001, which itself replaced the 17-35/f2.8L of 1996. I have not used the 2001 lens, but I can say that both current lenses are a significant improvement over the 1996 lens.

The 16-35/f2.8 is twice the price as the 17-40/f4, and the weight difference, although small, is noticeable on a body such as the Canon 5D. The 16-25/f2.8 also requires uncommon 82mm filters, while the 77mm filters for the 17-40/f4 can be shared with the 24-105, 24-70, 100-400, 70-200/f2.8, amongst others. Is there any benefit, besides the faster maximum aperture, and what is it useful for ?

Based on Imatest testing on a full-frame 5D mk2 (one of the most reliable methods to measure lens performance, see this post for details) both lenses yield comparable image quality, with no lens besting the other consistently across the focal range. Contrarily to what has been reported by others (whom I suspect got sub-par copies of the 17-40) I did not find any definitive advantage for the 16-35. Please note that I have tested 3 different samples of the 16-35, finding the sample-to-sample variation to be, for once, quite small. Full results for focals 17mm, 20mm, 24mm, 28mm, and 35mm are below. Click on any graph to enlarge.

The 16-35 has a slight advantage at short focal lengths, mostly in terms of edge sharpness, while at the longer focal lengths, the 17-40 has a slight advantage. I do not consider those differences to be that significant. Both those lenses yield good center sharpness, but are not so good near the edges, in particular when used at f2.8-f4.

Because in the past I have almost always used the lens stopped down to at least f8 for depth of field and better sharpness, the f2.8 aperture wasn’t that useful for me. Even if what you are after is out-of-focus blur, not much is generated by the additional f-stop, since the focals are so wide. Therefore, I think that for the majority of photographers and situations, the 17-40/f4 will do just as fine.

One specialized situation has came up recently, as I got more interested in night photography with star fields. In photographing stars, one is almost always using the highest acceptable ISO, as stars are faint light sources. Shutter speeds are limited by the movement of the earth. A shutter speed longer than 30s will cause stars to be renders as streaks rather than points. This leaves no choice but using the widest aperture available, and one f-stops makes a big difference here. If point stars are not involved, the 17-40/f4 might otherwise be the better choice for night photography, because its simpler construction make it more resistant to flare.

The results at f2.8 are sufficiently poor to warrant using a fixed focal length instead. I have tested, amongst others, the Canon 24/f1.4 II and the famed Zeiss Distagon 21/f2.8, which are both better at wide apertures, but this will be the subject for a different post. If one is carrying such a lens, the f2.8 aperture of the zoom becomes kind of useless, and therefore the 17-40/f4 would be a better choice.

There are situations (such as backpacking or light travel), where one would not wish to carry a separate lens just for a few night shots. Some photographers also do not want to own several wide-angle lenses. In my opinion, the 16-35/f2.8 is mostly useful for those situations when a single fast and versatile lens is required. In other words, get the 16-35/f2.8 if you plan to shoot wide-open, and it will be your only wide-angle lens, otherwise get the 17-40/f4.

Summary:

I have been spending quite a bit of time in Yosemite, and posting quite a few images for a project I’ll talk about later. To celebrate its completion, for the rest of the summer, I will be describing a few Yosemite locations that I visited recently. Their common characteristic is that they are out of the beaten path, yet each of them offers truly unique sights. I’ll start with a trilogy of “wilderness hikes” in Yosemite Valley, and then highlight a few high country locations.

Plunging from a cliff west of El Capitan for 1,612 feet (491m), Ribbon Fall is the tallest single-drop waterfall in North America. Yosemite Falls is considered higher (2,425 feet), but it consists of three sections, whereas Ribbon Fall is a continuous waterfall.

Another reason why Ribbon Fall is unique in Yosemite is that it flows into a high amphitheater of vertical cliffs to which you can hike, so that you would be standing right at the base of the fall, looking up directly at the amazing drop, surrounded by rock walls. The depth of the cirque cannot be appreciated from the road.

Hiking there feels almost like a wilderness experience, something so rare in the Valley. For the whole afternoon, I didn’t see anybody there. The rangers told me that there is no trail to the base of Ribbon Fall, so I didn’t look for one, heading straight up the slope on the right bank of Ribbon Creek. As the forest undergrowth is relatively sparse, I didn’t really need to do any bushwhacking, taking maybe two hours to reach the fall. The terrain was quite steep, but not exposed, being located entirely in the forest, with no cliffs. However, on the way down, I found a relatively nice user trail, well marked with cairns. To catch it, park on a pull out off the main loop road, a short distance West of El Capitan Meadow, then walk to the very end of the left (W) branch of the forestry road, and you’ll see a cairn marking the beginning of the trail.

Although it was quite warm in the Valley, I packed a sweatshirt and a light rain jacket, in case of a drop in temperature at the base. This drop was way more than what I expected. It got so cold, wet, and windy that I almost became hypothermic as I was waiting for the wind to blow in a different direction. The constant spray made it difficult to get a sharp image. When the wind would ease a bit, I’d point quickly the camera for a single shot, after which the lens would be soaked. I held as long as I could, more than one hour, then decided to leave the amphitheater when I began to shiver in an uncontrolled way.

If I was to come back, I’d start earlier in the day (the fall is best lit at noon), and pack a mountaineering-grade shell and a fleece jacket. Note that Ribbon Fall is seasonal, like Yosemite Fall, so you’ll probably have to wait until next spring to try this hike.

Part 1 of 6: 1 | 2 | 3 | 4 | 5 | 6

Check out my book: Spectacular Yosemite !

More images of Ribbon Fall

Last week, we waded in the water in a Everglades cypress dome. We will continue walking in the water this week, although in a different environment.

The Florida Keys form a chain of barrier islands beginning offshore of Miami, and extending for more than 130 miles to Key West. While almost the entire chain of Key Islands south of Miami is developed and linked by the amazing Overseas Highway, the northernmost of those islands, Elliott Key, has been preserved from development by the establishment of Biscayne National Park. Elliott Key is reached by a daily short cruise starting from the Biscayne National Park visitor center on the mainland.

As a barrier island, Elliott Key separates the Atlantic Ocean from Biscayne Bay. The two shores of Elliott present a drastically different character. While only rugged plants grow on the wave-battered ocean side, the bay side is lined up by the longest mangrove shore on the East Coast.

Even in February – a month with low humidity, heat, and mosquitoes – as I stepped into the water from the landing beach, it felt warm and inviting. The soft sand continued under my feet, even as I turned a corner, and the pier quickly disappeared from view. I could now see an unbroken line of trees with their dark green leaves reaching almost to the water, a sight much more interesting than from the island interior, where the trail was rather unremarkable. The mysterious place reminded me of the jungles seen in old movies. As I got closer, I observed between the water and the leaves an impenetrable tangle of prop roots, arching from the tree’s trunk to the water.

In order to be able to work easily, for a long time, with my full range of equipment, including my large format camera, I had brought a small inflatable boat. It was just the kind used by kids, but it was sufficient to hold my camera bag, providing me a platform from which to switch gear. As I towed it behind me, it glided effortlessly in the calm evening water. The setting sun illuminated the whole bay side shoreline. I set up my tripod in thigh-high water for one last long exposure, the camera just slightly above the water surface, then headed back to the beach around the impenetrable mangrove forest, as the light was fading.

As I retreated to the pleasant, grassy campsite close to the landing, I made sure to rinse thoroughly my carbon fiber tripod with freshwater, since I had been told at the Gitzo factory outside of Paris that my previous one had been ruined by that lack of maintenance. The lights of Miami began to shine across the bay. Yet the silent island felt like a world apart.

View more images of Biscayne National Park

On Saturday, I took a break from my work on Yosemite (more on it latter).

I first headed to 49 Geary, a building near Union Square, where several floors are occupied by world class art galleries, giving you the opportunity to see a variety of art in a single location.

The main draw of the day was a book signing with Michael Kenna at the Stephen Wirtz Gallery, which had also a great exhibition of his work, presenting classic images, as well as new work from Venezia. Book signings are a strange exercise, on both ends of which I’ve been before (although more often on the receiving end), where you are given the opportunity to a conversation of just a few minutes. As some of them have been crowded and rushed affairs, I appreciated the relaxed atmosphere, which let me enjoy an interesting exchange with the legend. By the way, Michael’s Kenna handwriting turned out to be as artistic as his imagery.

Browsing the building, I was pleasantly surprised to see that the Modernbook Gallery had just moved there, after ten years on University Ave in Palo Alto. Their owners, Mark and Bryan, are the most friendly, approachable, enthusiastic, generous, and helpful people in the gallery business. Their unexpected move was a great coincidence, as their current exhibition was of Fred Lyon work, who has been photographing the city for 7 decades.

Mark pointed to some other galleries not to be missed. Amongst them was an exhibition of Miroslav Tichy at Robert Koch Gallery. I had been intrigued by his story for a while. Using cameras he made himself from recycled garbage, with lenses of plexiglas, for decades, the eccentric and mysterious Tichy wandered every day the streets of his hometown of Kyjov photographing women surreptitiously. While I could appreciate the uniqueness of the story, as well as the “contemporaneity” of the blurred and off-kilter one-of-the kind tiny prints, I must admit that after looking at the work in person, I came away slightly perplexed by his meteoric rise in the art world, as an 80 year-old reclusive. That is, until I found, the next day, this article (in French, although with an English abstract) L’ Invention de Miroslav Tichy.

I then headed towards the Cliff House, site of a “Photo Walk” lead by Jim Goldstein ( see his photos). It took place at the Sutro Baths, a remarkable meeting of man-made and natural environments at the edge of the Pacific Ocean. Although it was one of those foggy evenings that must have inspired Mark Twain’s saying “The coldest winter of my life was a summer in San Francisco”, there was quite a bit to photograph. While normally I prefer to work alone, I was pleased to see several friends there, and had mostly a good time catching up with them. I actually liked to see photographers crawling all over the place. I even made … a few photographs ! To stay with that day’s mood, I am presenting two of them as a modest homage to Michael Kenna. I’ll let you guess about the third one.

On my first visit to Everglades National Park, I focused on the wildlife, the wading birds and alligators. Nowhere else in North America are the birds that diverse, abundant and easy to observe and photograph along one of the parks famous boardwalk trails.

The scenery at first appeared flat and monotonous, so I was content to find a few locations over water to photographs sunrises and sunset. However, as I took the more careful perspective of a landscape photographer, I recognized a variety of ecosystems that includes marshes, sawgrass prairies, pine forests, tropical hammocks, mangrove swamps, coastal beaches, and cypress domes. In this post, I will concentrate on the latter, since I believe that they offer one of the most unusual experiences in the National Parks, yet one which is accessible to almost everybody.

I first walked up the Pa-hay-okee observation tower to survey the swamp. Cypress are one of the most unique trees in the South, as they grow out of the water, forming swamp forests, called “cypress dome”. The term, “cypress dome” refers to the phenomenon that the larger cypress grow in the middle of the dome, and then get progressively smaller as one goes out from the center. The conditions for growth are more favorable in the center as opposed to the edges. Pa-hay-okee is the area of the park where many of the cypress domes grow.

Next, I picked up at random a nearby cypress dome, and parked on the side of the road at an unmarked spot. From a distance, the cypress dome looked like regular woods. As I stepped tentatively into the water of the “river of grass”, wearing long pants against the sharp blades of the appropriately named sawgrass, I was surprised to feel a solid ground underneath my feet, instead the mud I was expecting. I was walking directly on the hard underlying limestone bedrock of the Everglades, although I couldn’t see my feet through the dark water.

After a few hundred yards, as I began to get used to this strange feeling of “wet hiking”, I walked with more confidence. By that time, the road was no longer in sight. Instead, I was surrounded by a dense cypress forest rising from black water. As it was winter, the branches were bare of leaves, yet the trees were covered with bromeliads and orchids. Such a beauty and lushness just couldn’t have been anticipated from outside the dome. Although it has been only a short time, I felt like I was the only human being to have ever set foot on that primeval patch of water-covered ground.

Working from a shoulder bag, I set up my tripod in the water and began photographing. The overcast morning that I chose provided even illumination in the swamp, but I was careful not to include the overly bright sky in the images.

Everglades National Park is best enjoyed during the dry season, in winter. Although summer brings out dramatic thunderstorms clouds, the high temperatures, humidity, and mosquitoes make it uncomfortable. If you are hesitant to venture by yourself into the swamp, the rangers organize regularly guided walks. Do not miss such a unique experience, hidden to most visitors, although so close !

View all images of Everglades National Park
view images of cypress in Everglades

The Appalachians, largest mountain range in the Eastern US, culminates at its southern end in North Carolina and Tennessee. Those two states split Great Smoky Mountains National Park, which preserves one of the finest virgin deciduous forest in the world.

The top of Clingsman’s Dome is the highest point in the Park, at 6,643 ft (2,025 m). The only (slightly) taller mountain East of the Mississippi is Mount Mitchell 6,684 ft (2,037 m), northeast of Ashville, NC. Clingman’s Dome is extremely easy to access, as a 7-mile spur road, branching from the Newfound Gap Road, leads to a large parking lot near the top, from which the best photography spots are found.

From the peak, located almost at the center of the park, I found large gaps between trees – just at the edge of the parking lot – that framed great views over forested ridges, extending to the horizon. The Great Smokies were named for the fog that often hangs over the range. This fog is the result of warm humid air from the Gulf of Mexico cooling rapidly in the higher elevations of Southern Appalachia. It made the views more special by allowing me to create compositions with layers of ridges fading in the distance. Their progressively lighter tones provides the strong three-dimensional clue named “aerial perspective”, first used in paintings from the Netherlands in the 15th century, and then in the Mona Lisa.

The light is fine both at sunrise and sunset. At sunrise, I prefer to set-up the camera at the east end of the parking lot, while I find the west end preferable for sunset. I walked once to the top of observation tower, through a half-mile paved trail, but the view from the rounded summit wasn’t as interesting, that is unless one is interested in surveying dead trees.

Fog is more likely to be found in the morning. I set up my alarm one hour and half before sunrise. It took more than half an hour to drive there from the campground (same as from Gatlinburg). In the spring and fall, the temperature on the top often drops below freezing at night. I noticed icicles forming where streams drop onto the road Clingman’s Dome road. Arriving at the top 40 minutes before sunrise, as I stepped out of the car, I was greeted by temperatures much colder than at the campground. However, there was no temptation to retreat into the car, as an intense orange glow lit the eastern horizon, contrasting with the blue ridges. Since those ridges were backlit and quite darker than the sky, I used a graduated neutral filter to keep the contrast in check. After the sun came and illuminated the entire landscape, I switched to a wider lens, including foreground trees into my compositions. Although the sun got higher in the sky, I was still shivering from standing for a prolonged time in the cold, although by the time I drove down, the icicles had started to collapse.

Great Smoky Mountains it the most visited of all National Parks, so summer crowds can jam the roads, although it is usually pretty quiet before sunrise. Spring sees less visitation and a variety of blooms. With all this variety of deciduous trees, autumn offers a spectacular sea of colors which in general peak at mid-October at the higher elevations. However, I prefer to photograph the colors from the Newfound Gap road, where closer trees in fall foliage provide a more harmonious foreground. The Clingsman’s Dome road is closed in winter and doesn’t re-open until April.

View more images of Great Smoky Mountains National Park
View more images taken from Clingman’s Dome

They say “it just works”. However, over the last month, my Apple computer just crashed. The symptom is a “kernel panic”, with a message over the frozen screen advising to hold the power button. This first happened a few times a week, and then worsened to several times a day. After two other support people, I talked to a senior Apple tech person who guided me through a “archive and re-install” (which nevertheless broke quite a few of my applications) but eventually the problem resurfaced. Very annoying for a relatively high-end Mac Pro configuration with 2x Quadcore 2.8, 10GB RAM, 2 internal 1GB drives and 2 raided Raptors.

The next step was to do the dreaded clean install, that is to format a brand-new drive, re-install mac OS (I also upgraded to 10.6, Snow Leopard), reinstall each of my applications individually, and restore my data from backup.

I wasn’t looking forward to it, since I knew it would take most of the week-end. You’ll understand why when you see the software installed. While some of them applications are quick to install, others took some time (Windows XP), extensive reconfiguration of preferences (Photoshop), or experimentation (Parallels, ImageMagick).

For each of the applications, I searched on the web to find the most up to date version, as well as tips to resolve problems. I am wondering how we were ever able to use computers before the web days. For instance, to get the Samsung printer to work, you had to open system pref>printer & faxes> and then to right click in the *blank* space below the list of printers in order to reset the printing system before trying to add the printer again.

So what’s the result of this “fun” week-end ? More kernel panics, apparently related to external drive operations. Grrr ! Any ideas, besides switching to Windows ?

Maybe the only upside is a cleaner (but still faulty) system, which at least doesn’t crash while doing nothing, and for you, reader, an opportunity to take stock of the software I am running, in case you’re curious:

1. Drivers
   • Microsoft keyboard
   • Kensington mouse
   • SpectraView driver/calibrator for NEC display
   • Samsumg ML 1700 driver
   • Epson 1800 driver
   • Vuescan for Nikon LS 4000 scanner
   • Silverfast for Epson 4870 scanner
2. System Applications
   • Firefox + Google toolbar
   • Thunderbird
   • Microsoft Office
   • Carbon Copy Cloner
   • Synchronize X plus
   • Macaroni
   • Tweetdeck
   • Aquamacs Emacs
   • Google Earth
   • Gpsbabel
3. Imaging Applications
   • Adobe Creative Suite
   • Noise Ninja PS plug-in
   • Photokit sharpener PS plug-in
   • Genuine Fractals PS plug-in
   • Lightroom
   • DxO Optics Pro
   • AutoPano Pro
   • Quicktime 7 Pro
4. MS Windows Applications
   • Parallels desktop
   • Windows XP on Boot Camp
   • Imatch on Windows XP
   • Imatest on Windows XP
   • Trackstick Manager on Windows XP
5. Server Applications
   • Xcode
   • MySQL
   • ImageMagick (including jpeg,tiff,png,freetype,lcms)
   • exiftool
   • Image-IPTCInfo
   • perl DBI
   • perl DBD::mysql

The observant readers may have noticed that the list doesn’t include the Epson 9800 printer driver. Since printing is such a business-critical task, I have dedicated an older computer (a G5) to driving the printer with an older version of Photoshop. I’ve read that there has been quite a few color management problems with newer versions. On the other hand, unlike my Mac Pro, the G5 has been running like a champ !

Over 300 miles of caves have been mapped in Mammoth Cave National Park, making it the largest known cave system in the world. Depending on the season, the National Park Service offers up to a dozen different tours into the caves.

Although some of the tours can last up to 6 hours, most of the chambers do not contain intricate cave formations. The most beautiful area of the cave is the Frozen Niagara section, where stalactites and stalagmites are found in abundance. After descending a few hundred stairs, the rest of the distance is less than a mostly horizontal mile, finishing in a room heavily decorated with flowstone. On the way, you pass intriguing sights, such as Crystal Lake. Long tours visit the Frozen Niagara section only briefly. For this reason, I recommend to photographers the “Frozen Niagara” tour, which spends all of its time (total about 2 hours, including transportation by bus for a couple of miles from the visitor center to the “New” cave entrance) there. This has the additional advantage of leaving you some time to explore the surface terrain, which is quite interesting in its own right. Buy the tickets for your tours as you arrive, since tours can sell out fast during the day.

Unlike in Carslbad Caverns, Park regulations make it difficult to photograph.

First, tripods are strictly prohibited. Since the light levels are relatively low, this leaves you with few options. You can use flash, but it will be a challenge to light the cave formations in a pleasant way. The best method I have found is to bring a Bogen Super Clamp which works very well on the tubings of the cave railings. The clamp is inexpensive and very sturdy. I have used it to photograph with a large format camera in the cave, and it provided enough rigidity ! To attach your regular tripod head, you’ll find on the top a 1/4 inch threaded hole in which you can screw in a stud. Since most tripod heads have a 3/8 inch thread, you will probably need a 1/4 to 3/8 reducer bushing as well. You can walk around with the ball-head and clamp attached to your camera. I have found this set up particularly effective for photographing Crystal Lake from the shaft above.

Second, you will be in a tour group, as there are no self-guided tours. A ranger trails the group to keep stragglers moving, so it’s not possible to stop very long to photograph. The best bet would be to place yourself at the end of the group, since at the beginning of it, other visitors want to keep up with the other ranger to listen to his commentary during the half-dozen stops during the visit. More tours are offered in the summer, however the other seasons see fewer crowds (tour groups can number up to 100) and therefore tour groups that are smaller and more relaxed, with possibly more flexible rangers. Towards the end of October, the surrounding woods display beautiful fall colors.

It is easy to dismiss at a first glance Hot Springs National Park. The smallest of the US National Parks (just over 5,500 acres) consists mostly of Central Avenue, the main street of Hot Springs, Arkansas, and seemingly undistinguished hills.

So why is it the oldest area in the National Park System, set aside as a special reservation in 1832, a full 40 years before Yellowstone became the first National Park ?

At that time, Hot Springs had already became famous as a heath spa where people “took the waters” that come from the 47 hot springs flowing in the surrounding hills. While the man-made nature of the row of well-preserved historic bathhouses is clear, it is less obvious that the hill above this row, Hot Springs Mountain, is a man-made landscape. Tufa once coated it, and waters ran over it. The waters were diverted in a plumbing system, and the slope covered with dirt and vegetated. The artificial landscape is interesting to observe, in its gradual transition from city to woodland, with the Grand Promenade bridging them. Fall brings spectacular colors to the woods, as bright as any other place in the southern Appalachian mountains.

In the early 80s, a spot was cleared of dirt so that a hot spring could be seen again. This spot, called the Cascade, past Bathhouse Row, near the intersection of Central Avenue and Fountain Street, remains the only place in the park to view hot water cascading over tufa terraces.

The cascade is most interesting to photograph early in the morning, when the cooler temperatures give rise to denser steam. At that time of the day, it is still in the shade, and therefore uniformly lighted. You can observe the whole cascade from the base, or walk up stairs to a point that offers close-ups views of the water, tufa, and blue-green algae.

View all images of Hot Springs National Park

About a decade ago, I switched from Nikon to Canon. I was attracted, among other things, by the availability of a 24mm tilt and shift (T/S) lens, which brings to 35mm some of the controls available to the large format camera photographer. While it has served me well, its T/S functions making it possible to create higher quality images than would have been possible with a regular lens, it had a number of shortcomings. My main gripe was that there wasn’t enough of an image circle to shift fully the lens in vertical orientation. I also wished that the image quality was better, since when used as a regular lens, it wasn’t even as sharp as my zooms, and suffered from serious chromatic aberration.

Last year, maybe challenged by Nikon’s new great 24 T/S lens, Canon introduced a revision of their own 24 T/S lens. It is in fact an entirely different lens, physically quite similar to the Nikon. The goal seems to have been to produce a high performance lens, regardless of size and weight, which are all significantly larger than the previous version.

Did Canon deliver on their promise of a high-performance lens ? As the Imatest (best way to measure lens performance, see details here) charts below show, the answer is an unqualified yes ! The new lens is impressively sharp even wide open, with corners almost as good as the center, which is extremely rare for a wide angle lens. It boasts a significantly larger image circle, which now allows a full 12mm shift in both horizontal and vertical orientation. In fact, it has been reported that the image circle is so large that the new lens can be used with a medium format camera. Controls are much improved. The ability to use independent axis for tilt and shift (unique to the Canon design) is a nice bonus.

Both lens are manual focus with focus confirmation, automatic aperture, and a solid all-metal construction. The table below summarizes the differences I have found between the two lenses. There are so many improvements that I feel that the new lens is well worth its price, despite it being almost twice as much the price of the old lens.