For several years, I have been trying to photograph a tree with white bark, such as a birch tree, so the bark looks and feels really white. I have tried several times but never obtained a photo that inspired me.
During 2016, I was traveling on Highway-113 in British Columbia, Canada, near Alaska’s southernmost border. The area was heavily wooded (as is much of western Canada) and a good variety of tree types were present. Trees on both sides of the road were cleared from the first fifty feet of the shoulder area and only head-high brush remained in the fifty feet area.
A diverse mix of trees was present at the forest edge, including some white barked trees (I think birch). The forest edge on one side of the road was drenched in direct sunlight whereas the forest edge on the other side was illuminated only by blue sky (i.e. indirect sunlight). The forest interior on the side that was illuminated only indirectly looked more uniformly dark so I concentrated on that side of the road. I reasoned that the uniformly dark forest interior would provide a simpler background to contrast with a white tree at the forest edge. That is, the white tree would look more stark and isolated.
As I drove slowly and looked, I tried to compose a photograph in my head. I looked for a white tree trunk located as close to the forest edge as possible where it was illuminated with lots of light to contrast with the dark forest interior. After about eight miles I found the tree I wanted. It stood at the very edge of the forest (and thus was quite bright) and was in front of other types of trees that were located a bit farther from the forest edge (and thus were quite a bit darker).
I parked and walked fifty feet to the forest edge and looked through my viewing filter to find a suitable composition. The viewing filter is a piece of opaque black plastic with a small hole about 1 1/8 inch x 1 3/8 inch (the same proportion as my 4 inch x 5 inch film). An orange-yellow filter covers the hole and allows the scene to be viewed in monochrome with tonal relationships that are similar to black & white film.
Unlike my big, heavy camera and tripod, the viewing filter is nearly weightless and hangs conveniently on a string around my neck. I use a viewing filter for my initial evaluation of most scenes since it allows me to move easily while searching for a composition without carrying a heavy camera and tripod. Once I find a composition that I like with the viewing filter, I know where to place my tripod, which lens to use and what scene elements to include in the image.
I found a composition I liked and put a rock on the ground where I wanted to place my tripod. Foreground brush was six feet tall and had to be removed so I walked back to my vehicle to retrieve a machete which I carry for situations like this. I hacked down the brush (which would have been mowed soon to keep the fifty feet area clear) and then retrieved my camera, camera bag and tripod. I found the rock identifying my tripod location mark and assembled my photographic equipment.
The main elements of the composition were a white tree trunk, three darker tree trunks and a few branches from a conifer tree. The overall concept of the photo was to contrast the white tree trunk with a darker background which included the three darker tree trunks and branches. I hoped the contrast would help the white trunk feel different than the other trees. The composition and concept were simple and it was important to eliminate other objects from the composition.
One way to isolate subjects that are wanted in the photograph by eliminating unwanted objects from the image is to use a lens of long focal length. I mounted the longest focal length lens that I had (305 mm lens) on my 4 inch x 5 inch view camera (150 mm is a “normal” focal length for 4×5 cameras). The lens helped isolate and emphasize the four trees and conifer branches in the composition.
Since the subjects of my photograph were real trees, it was important to get their geometry correct so they looked realistic in the image. One of the many advantages of a view camera is its ability to easily adjust image geometry using bubble levels and swing/tilt adjustments of the camera.
Trees grow more-or-less vertically so my initial task was to accurately align the film plane parallel to the vertical plumb line to eliminate parallax. This had two important benefits. First, plumb alignment ensured that the image depicted the actual widths of the trees rather than widths which unnaturally narrow toward one end as they do in images with parallax. Second, eliminating parallax ensured that the image showed the true direction of tree growth rather than trees with unnatural lean. To me, there are few things that make a photo look more “artificial” than trees (or buildings) on the right side of an image leaning toward the left and trees (or buildings) on the left side leaning toward the right. Alignment was accomplished in five seconds using a bubble level on my view camera.
My next alignment task aligned the film accurately parallel to the horizontal level (left-to-right). This ensured that the upward growth direction of each tree at the scene was represented accurately in the image. That is, trees grow more-or-less vertically but there are variations between individual trees. Leveling the camera allows the real growth direction of each tree to be recorded accurately. For me, recording the true variations in the direction of tree growth helps landscape photographs look and feel more realistic. Horizontal leveling was accomplished in five seconds using another bubble level on the camera.
Next, the lensboard was aligned parallel to the vertical plumb (and the film plane) to ensure that the lens’s plane of focus was vertical (like the trees). Lensboard alignment is especially important when using a relatively large lens aperture (i.e. small f-stop) which produces a shallow depth of focus. For today’s photo, a shallow depth of focus was needed because I wanted the four trees and conifer branches to be sharply focused but I didn’t want other objects in the forest to be focused. Lensboard alignment was accomplished in five seconds.
The ability to vary the location of a lens’s focal plane within scenes is a major advantage of view cameras and can be employed to achieve image sharpness through great scene depth. In landscape photography, I usually tilt the lensboard slightly forward to locate the lens’s focal plane so it covers both the scene’s foreground and background objects so sharp image focus is achieved throughout the scene depth. For today’s photo, the focal plane was positioned vertically to ensure that the entire length of all four trees were located within the lens’s focal plane even though a relatively large lens aperture was used to produce a shallow depth of focus and keep other objects in the forest out of sharp focus.
After my camera adjustments were completed, I carefully focused the lens and then tightened all knobs on my camera. As is the case for most landscape photographs, the composition was not perfect but I thought that it contained the essential elements that I needed to make a good image. I was excited at the thought of what this photograph could become.
I thought that it was best to optimize the film’s exposure and development for the white tree since it was the most important image element. I acquired a few light meter readings with my 1-degree spot meter and placed the white tree’s brightest areas on Zone VI (one f-stop brighter than middle gray). The three darker trees and conifer branches were quite dark but contained enough detail for them to be brightened later during editing. Most objects deeper in the forest were extremely dark. I marked the film’s exposure record for N+1 development to increase image contrast on the film one f-stop by moving the white tree from Zone VI (one f-stop brighter than middle gray) to Zone VII (bright with good detail).
One sheet of Tri-X black & white film was exposed at 1/15 sec and f/16.
After development, the 4 inch x 5 inch film was mounted in fluid and drum-scanned at my usual resolution of 5,000 ppi (pixels per inch) and 16-bit pixel depth to obtain a high-resolution black and white digital image of nearly one GB in size.
The image obtained from the scanner without editing is shown below. The two trees on the right were darker than I expected and would have benefited from more exposure. However, the mistake was not fatal because they contained enough structural detail (probably not visible in this low resolution web image) to be brightened during editing. The scanned image showed several small specks of bright light that resulted from direct sunlight piercing the forest canopy and illuminating small branches within the forest. I probably should have opened the lens aperture a bit more (f/11 rather than f/16 ) to reduce its depth of focus so more of the small specks would be out of focus and thus less prominent. Although the raw image certainly wasn’t perfect, it contained all of the information I needed to make it into the image that I wanted.
Note that no parallax or other geometrical artifacts are identifiable in the image. To me, the trees look natural.
A PhotoShop Curve Adjustment Layer was opened and its user interface is shown below. Tones progress from light-to-dark beginning at the lower left corner.
The histogram of the scanned film shows that every gray tone was occupied with pixels. The forest interior looked quite dark at the scene and the largest histogram peak was associated with the dark forest interior.
The population of extremely bright pixels was very small so I reset the white point of the histogram by moving the white slider slightly to the right to produce a slightly larger population of pure white pixels. Then, I bent the curve slightly upward near the bright end of the histogram to slightly darken bright (but not pure white) pixels to enhance structures within the bright tree trunk. That effect is likely not visible in the low resolution web image shown here but it definitely emphasized structural details in the white trunk and help it feel more solid and real.
The black slider was moved left a small amount to slightly strengthen the dark inner forest (i.e. increase the population of pure black pixels).
Finally, the middle region of the curve was bent down to brighten tones of the two trees and conifer branches on the right.
The effect of Curve adjustment on the image is shown below. Overall, it is more like the image that I sought from the beginning.
Next, local retouching was performed using PhotoShop’s Burn, Dodge and Clone tools. The original image layer from the scanner was duplicated, named “Retouch” and placed directly above the scanner layer.
The overall goal of retouching was to visually set the white tree apart from the other three trees and conifer branches. My thinking at the scene when the photo was acquired was to contrast the brightness of the white tree with the other three trees and conifer branches. However, I realized during editing that the contrast would feel stronger if the three trees and branches all had similar gray tones. Doing that would cause the three trees and branches to visually become “the forest” so the white tree would be brighter than “the forest” as opposed to being slightly brighter than one tree, moderately brighter than another tree and so on. Consequently, Dodge and Burn tools were used to render the three trees and branches with the same approximate gray tones.
Since the main subjects in my photograph were simple tree trunks, it was important to eliminate objects from the composition which added unneeded complication. Burn, Dodge and Clone tools were used liberally to simplify the image. The small bright specs deep in the forest were removed to eliminate their distractions. Many small tree branches which entered the image at its edges were removed to maintain focus on the four trees. Finally, a few small branches of the four main trees were removed to further simplify the image.
The image after all retouching is shown below. The retouched image was simpler and the white tree felt more different than every thing else in the image. I was beginning to be happy with the photograph.
I looked at the image for quite a while and decided that the white tree could feel even more different than the other trees. I opened a second Curve Adjustment Layer and placed it directly above the first Curve Adjustment Layer to modify the image without disturbing the first Curve adjustments. The second Curve adjustment had two primary objectives.
First, I wanted to make the white tree brighter. Most of the white tree was as bright as I thought possible so I focused mostly on large gray areas near both trunk edges (the sides of the tree). Some gray tones were needed on the trunk sides, however, since they helped inform the viewer that the trunk was round. Consequently, my approach was to change the large gray side areas into smaller areas of gray by brightening some of the gray tones.
The Curve adjustment interface is shown below. The curve for the left half of the histogram was bent downward to brighten light gray image tones. Note that the number of pure white pixels was not changed and very bright (but not pure white) pixels were lightened only slightly but less bright pixels were lightened more. Image tones which straddle the histogram’s leftmost vertical line marker corresponded mostly to the large gray areas on both sides of the trunk and those pixels were lightened the most.
The second goal of the this Curve adjustment dealt with darker areas of the histogram which corresponded to the other three trees and conifer branches. Gray tones in some areas of these objects were too bright so I bent the curve upward to darken the areas and flatten the curve for the three trees and branches.
Curve flattening straddles the histogram’s rightmost vertical line marker in the Curve interface. Flattening the curve for the three darker trees and branches produced more uniform gray tones so their structural details were less prominent in the image. That effect was important for this photo because it created another difference between the white tree and other trees in the image. That is, the white tree became different than the other trees because the bright white tree (a) exhibited brighter tones than the other trees and (b) showed substantially more structural detail than other trees.
The image below includes the second Curve adjustment. To me, the white tree looks and feels really white and really different than the rest of the forest. The contrast is simple and powerful.
“Trees Near Gingolx” looks much better as a high resolution print than as a low resolution web image. High resolution prints reveal a considerable amount of detail in the white tree trunk which is important because it helps differentiate the white tree from other objects in the image. As is usually the case, looking at low resolution images on the web is great but there is no substitute for seeing a high resolution print in person.
The subject of this photograph was the difference between a tree with white bark and other trees in the forest. I believe “Trees Near Gingolx” shows that difference in a simple and powerful way. A decision was made to carefully avoid parallax and other geometrical artifacts so the trees in this photograph looked realistic and natural.
Any comments you might have about the image, the photographic approach used for it, its composition, or image workup will be appreciated. For a slightly better view of this photograph, visit here.
Randall R Bresee