Tilting at Trilliums
A special lens solves a common problem.
April 27, 2016 Landscape / Wildflowers
On any mid-April or early-May day I'm at home, you'll find me in the woods. The spring wildflowers of the Eastern deciduous forests here are botanical sirens whose songs I cannot resist. When I'm not with them, I'm thinking about them. And once I'm back among them, the only things that can separate us are the failing light of evening or my wife calling to say she's leaving the office.
If I have anything like an obsession in my life, it's these wildflowers. Mind you, I've hiked woodland trails from Minnesota and Michigan to North Carolina and Georgia in search of the fleeting flowers of spring. But I've never come across a densely-packed display like the one in this park 30 minutes from home.
It's a spring parade of the native herbaceous perennials scientists call "ephemerals" since they may bloom and disappear in a matter of a week or two. Even though each species makes a short appearance, the succession of blooming stretches the show to a month and a half in a good year. If it's unusually warm, the calendar gets compressed. When it's cool, the season stretches out. And I always wish for a cool spring.
The ephemerals must start early if they are to gather enough moisture and sunlight before the deciduous trees leaf out. Once the beech-maple canopy fills in, the forest floor is a darker place for the crucial photosynthesis that guarantees the survival of the wildflowers. And the competition for water is just as vital as these plants share the space at the feet of mature trees that are always thirsty in the spring.
The blooming of the ephemerals in these woods starts with the tiny Harbinger-of-spring (Erigenia bulbosa) and ends with the a big show of the Large-flowered trillium (Trillium grandiflorum), also called white trillium. In between them, another 20 species spring up and fade away. If the succession was a symphony, it would start with a gentle string solo, slowly build to a movement of many instruments, and finish with the crescendo of these large, white blossoms.
Today, I'm here when the white trilliums are at their peak, full of prime, perfect flowers. The subtle perfume of the mid-spring flowers has faded. Now it's all about the stunning sight of white as far as you can see through the woods.
I'll come back here a few more times when the trilliums take on a rosy blush as they fade. Then I'll turn my attention to returning songbirds or places far from home. But as sure as the seasons ebb and flow, the sirens of spring in this forest will call me back next April. And as always, I will be too weak to resist them.
MAKING THE PHOTOGRAPH (Techniques for Photographing Landscapes)
SUBJECT: Large-flowered trilliums (Trillium grandiflorum), Bendix Woods County Park, Indiana
CONDITIONS: Cool, fairly calm winds, lightly-overcast sky
EQUIPMENT and SETTINGS: Nikon D810, manual 35mm tilt lens, polarizing filter, tripod, cable release, Manual mode, Matrix meter, Manual focus
EXPOSURE: 1/15 sec at f/11, ISO 640
TECHNIQUE: In the spring when I'm not on the road, this woodland preserve is my home and office. Or so it feels when the forest's flowers are blooming. I've spent many quiet days along the trails, photographing flower portraits and big scenes. This section is a state nature preserve inside a well-loved county park. But I'm always surprised how few people walk these trails, even at the peak of the season. I can be here all day and see no one else.
There's no need to step off the trails here. The wildflowers are so abundant and healthy that they press right up to the edges of the narrow paths. That's fine, because as a state preserve, the rules ask us not to venture off the trail. There are many threatened and endangered species here that are too delicate to survive even one footstep on them.
I chose the spot for the photograph above along a trail I know well. I'd been watching this patch of trilliums come along for weeks. Today, the flowers and the conditions were good for a composition that showed them in their environment.
This was a fine time to use a lens that's an old friend. It's truly an antique in the age of digital photography, but it does something no other lens in my bag does. It's front element can tip up or down as it pivots independently from the camera body and the lens mount.
It's an old Canon manual 35mm tilt/shift lens. Years ago, someone stripped off its Canon mount and added a Nikon mount instead. In the process, the shift function was lost. But the tilting is what I wanted most when I bought it used from a California camera store in the mid-'90s.
True, there are modern tilt/shift lenses made by both companies, but back then only Canon had them. I've grown to know it's perspective so well that I can see a composition for it before I bring it out of the bag. Someday I'll break down and get the new Nikon tilt lenses -- for now I'm happy with this old companion.
(Update: In January 2017, I retired the old 35mm tilt lens and added the modern Nikon 45mm PC-E f/2.8D ED tilt/shift lens to my bag. Next spring, I'll revisit some spots in hopes of making compositions as comparisons between the two. But the easier operation and modern optics make me anticipate better images. And I know I'll be more motivated to tilt at a lot more scenes and subjects to come.)
The ability to tilt the front element down -- which is what I do most often -- makes it possible to get more depth of field in a scene without using a small aperture like f/22. That means I can use a faster shutter speed when wind and subject movement are concerns and still get the desired sharpness near to far.
A tilt lens employs a rule of optics called the Scheimpflug Principle. It's definition can be a lengthy scientific description laced with the mathematics that gave me night sweats as a student.
In it's simplest explanation, it says when the plane of a subject, the plane of the camera's film or sensor and the plane of the lens all intersect at one point, the entire plane of the subject is in focus.
With standard lenses, all three of these planes are fixed -- the plane of the scene is horizontal or nearly so, and the planes of the sensor and lens are vertical. The only way to gain depth of field with this set up is to tip the camera down a little, stop the lens down to a small aperture and extend the vertical plane of sharpness near to far.
A tilt lens changes the rules when the plane of the lens tips down (for landscapes) to the position where it intersects the point at which the other two planes meet. Now the plane of sharpness can fall across the plane of the scene and enough depth of field can be accomplished at middle apertures like f/11. This way we gain sharpness near to far and at faster shutter speeds, too. If the principle is still muddy in your mind, call it "camera magic" and trust that it truly works.
Back to the photograph above, I attached the old tilt lens with a polarizer on it to the camera body and flipped it to the vertical format. I tipped the camera down until I saw the scene from my toes to the far-off edge of the forest. This gave me a start at the tilting process since the sensor and lens planes weren't vertical anymore. I brought in the tripod, attached the camera to it, carefully recomposed the scene I saw when it was handheld, checked for clean frame edges without distractions, and turned the polarizer for its best effect.
Next, I opened the lens aperture wide to f/4, so I had a brighter image in the viewfinder. I focused on the foreground flowers and checked it with the focus-confirmation light each time I moved the focus point from flower to flower. Then I moved the focus sensor to the upper half of the frame. It indicated it wasn't focused there. I tilted the lens with its tilt-control knob just a bit until the light said it was focused. Then I moved the focus point back down to the flowers in the bottom half of the frame. It showed they were a bit out of focus. A slight adjustment of the focus ring brought them into focus again. I moved the focus point back to the upper half of the frame and saw it was focused, too. I was surprised because I usually have to repeat the process, making smaller changes each time until near and far points are in focus at the same time. "Patience" may be the best mantra to repeat as you work through the progression of focus, tilt a bit, refocus, tilt less, refocus, tilt a bit more, refocus...
Now that the plane of focus fell across the tops of the trilliums, I stopped down to f/11 for more depth of field, which in this case meant sharpness from the tops of the flowers to the tops of the trees in the distance. I clicked a frame and checked the histogram. It showed I was underexposing the scene. Since I was using manual settings, I added light by dialing in a slower shutter speed, since I didn't want to change the aperture and its depth of field. Finally, I was ready to make my photograph.
From this long description, you'd think that by the time I made the image, the flowers had faded, the seasons had changed and the world had forgotten about me. Luckily, the process is faster than its explanation. And I'm equally fortunate that Mary has been to enough workshops and with me in this forest that she gets it. When she called and asked what I was doing, I said "tilting at trilliums" and she knew just what I meant.